PELTIER_BED

MarlinFirmware/Marlin#27334
This commit is contained in:
Scott Lahteine 2024-10-06 10:48:57 -05:00
parent d5115be634
commit f494e96598
376 changed files with 12784 additions and 0 deletions

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@ -844,6 +844,40 @@
//#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