✨ PELTIER_BED

MarlinFirmware/Marlin#27334

config/default/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/3DFabXYZ/Migbot/Configuration.h

@@ -806,6 +806,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/3DMatik/XL/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/ADIMLab/Gantry v1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/ADIMLab/Gantry v2/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Alfawise/U20-bltouch/Configuration.h

@@ -873,6 +873,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Alfawise/U20/Configuration.h

@@ -874,6 +874,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AliExpress/CL-260/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AliExpress/UM2pExt/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/A2/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/A2plus/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/A6/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/A8/Configuration.h

@@ -807,6 +807,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/A8plus/Configuration.h

@@ -806,6 +806,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/A9/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/E10/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/E16/BTT SKR 1.3/Configuration.h

@@ -806,6 +806,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/E16/Stock/Configuration.h

@@ -806,6 +806,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET4+/Configuration.h

@@ -810,6 +810,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET4-Pro/Configuration.h

@@ -810,6 +810,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET4/Configuration.h

@@ -810,6 +810,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET4X/Configuration.h

@@ -810,6 +810,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET5-Pro/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET5/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Anet/ET5X/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/Chiron/Configuration.h

@@ -807,6 +807,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/Mega Zero 2.0/Anycubic V1/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/Mega Zero/Anycubic V1/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/Mega Zero/BigTreeTech SKR Mini MZ V1.0/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/Vyper/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/i3 Mega/Trigorilla AVR/Configuration.h

@@ -843,6 +843,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/i3 Mega/Trigorilla Pro STM32/Configuration.h

@@ -811,6 +811,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/AnyCubic/i3/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/ArmEd/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Genius Pro/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Genius/BLTouch/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Genius/V1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Hornet/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Sidewinder X1/0.9 BMG - E3D V6/Configuration.h

@@ -819,6 +819,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Sidewinder X1/V1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Artillery/Sidewinder X2/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Azteeg/X5GT/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIBO/TouchX/cyclops/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIBO/TouchX/default - BLTouch/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIBO/TouchX/default/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIQU/B1 SE Plus/Configuration.h

@@ -802,6 +802,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIQU/B1 SE/Configuration.h

@@ -802,6 +802,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIQU/B1/Configuration.h

@@ -811,6 +811,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIQU/BX/Configuration.h

@@ -812,6 +812,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIQU/Hurakan/Configuration.h

@@ -807,6 +807,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BIQU/Thunder Standard/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BQ/Hephestos/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BQ/Hephestos_2/Configuration.h

@@ -818,6 +818,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/BQ/WITBOX/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/CNC/miniRambo/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/CTC/A13/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/CTC/Bizer/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/CTC/i3 2560 Rev A/no probe/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Cartesio/Configuration.h

@@ -820,6 +820,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Copymaster3D/300/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Copymaster3D/400/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Copymaster3D/500/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 Max/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 Mini/BigTreeTech SKR Mini E3 2.0/Configuration.h

@@ -812,6 +812,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 Mini/BigTreeTech SKR Mini E3 3.0/Configuration.h

@@ -812,6 +812,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 Mini/CrealityV1/Configuration.h

@@ -813,6 +813,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 Mini/MEEB-3DP/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 S4/CrealityV1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 S5/BigTreeTech SKR Mini E3 1.2 with TFT35 E3 V3.0/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 S5/BigTreeTech SKR Mini E3 v3/Configuration.h

@@ -803,6 +803,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 S5/CrealityV1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 S5/CrealityV2.2 - BLTouch/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 S5/CrealityV427 - BLTouch/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 V2/Configuration.h

@@ -813,6 +813,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10 V3/Configuration.h

@@ -813,6 +813,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10/BigTreeTech SKR Mini E3 2.0/Configuration.h

@@ -803,6 +803,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10/BigTreeTech SKR Mini E3 3.0/Configuration.h

@@ -803,6 +803,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10/CrealityV1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S Pro/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/BigTreeTech SKR 1.4 Turbo TMC2209/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/BigTreeTech SKR 2.0 TMC2209/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/BigTreeTech SKR Mini E3 2.0/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/BigTreeTech SKR Mini E3 3.0/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/BigTreeTech SKR Pro v1.2/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/CrealityV1 - BLTouch/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-10S/CrealityV1/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-20 Pro/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-20/RepRapWorld Minitronics20/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-20/Stock/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-30 PrintMill/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-6 SE/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/CR-8/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-2 Pro/CrealityV24S4/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-2 Pro/CrealityV423/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-2/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-3 Max Neo/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-3 Max/Configuration.h

@@ -806,6 +806,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-3 Neo/Configuration.h

@@ -805,6 +805,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-3 Pro/BigTreeTech SKR 1.4 Turbo/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE
 

config/examples/Creality/Ender-3 Pro/BigTreeTech SKR Mini E3 1.0/Configuration.h

@@ -804,6 +804,40 @@
   //#define BED_LIMIT_SWITCHING   // Keep the bed temperature within BED_HYSTERESIS of the target
 #endif
 
+/**
+ * Peltier Bed - Heating and Cooling
+ *
+ * A Peltier device transfers heat from one side to the other in proportion to the amount of
+ * current flowing through the device and the direction of current flow. So the same device
+ * can both heat and cool.
+ *
+ * When "cooling" in addition to rejecting the heat transferred from the hot side to the cold
+ * side, the dissipated power (voltage * current) must also be rejected. Be sure to set up a
+ * fan that can be powered in sync with the Peltier unit.
+ *
+ * This feature is only set up to run in bang-bang mode because Peltiers don't handle PWM
+ * well without filter circuitry.
+ *
+ * Since existing 3D printers are made to handle relatively high current for the heated bed,
+ * we can use the heated bed power pins to control the Peltier power using the same G-codes
+ * as the heated bed (M140, M190, etc.).
+ *
+ * A second GPIO pin is required to control current direction.
+ * Two configurations are possible: Relay and H-Bridge
+ *
+ * (At this time only relay is supported. H-bridge requires 4 MOS switches configured in H-Bridge.)
+ *
+ * Power is handled by the bang-bang control loop: 0 or 255.
+ * Cooling applications are more common than heating, so the pin states are commonly:
+ *   LOW  = Heating = Relay Energized
+ *   HIGH = Cooling = Relay in "Normal" state
+ */
+//#define PELTIER_BED
+#if ENABLED(PELTIER_BED)
+  #define PELTIER_DIR_PIN           -1  // Relay control pin for Peltier
+  #define PELTIER_DIR_HEAT_STATE   LOW  // The relay pin state that causes the Peltier to heat
+#endif
+
 // Add 'M190 R T' for more gradual M190 R bed cooling.
 //#define BED_ANNEALING_GCODE