✨ M265 I2C_SCANNER (#28117)

Marlin/Configuration_adv.h

@@ -4718,6 +4718,11 @@
 //
 //#define PINS_DEBUGGING
 
+//
+// M265 - I2C Scanner
+//
+//#define I2C_SCANNER
+
 // Enable Tests that will run at startup and produce a report
 //#define MARLIN_TEST_BUILD
 

Marlin/src/gcode/feature/i2c/M265.cpp

@@ -0,0 +1,69 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2025 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "../../../inc/MarlinConfig.h"
+
+#if ENABLED(I2C_SCANNER)
+
+#include "../../../libs/hex_print.h"
+#include "../../gcode.h"
+#include <Wire.h> // Include Wire library for I2C communication
+
+/**
+ * M265: I2C Scanner - Scan for I2C devices on DOGLCD I2C pins
+ *
+ * Usage: M265
+ *
+ * Scans I2C addresses 0x08 to 0x77 and reports any responding devices.
+ */
+void GcodeSuite::M265() {
+  Wire.begin();
+  int device_count = 0;
+
+  SERIAL_ECHOLNPGM("Scanning I2C (0x08-0x77)...");
+  for (uint8_t address = 0x08; address <= 0x77; address++) {
+    Wire.beginTransmission(address);
+    const uint8_t error = Wire.endTransmission();
+
+    if (error == 0) {
+      // Device found
+      device_count++;
+      SERIAL_ECHOLNPGM("I2C device found at address 0x", hex_byte(address));
+    }
+    else if (error == 4)
+      SERIAL_ECHOLNPGM("Unknown error at address 0x", hex_byte(address));
+
+    safe_delay(5);  // Small delay between scans
+  }
+
+  SERIAL_ECHOPGM("I2C scan complete. ");
+  if (device_count == 0)
+    SERIAL_ECHOLNPGM("No I2C devices found");
+  else {
+    SERIAL_ECHOLN("Found ", device_count, " device");
+    if (device_count > 1) SERIAL_CHAR('s');
+    SERIAL_EOL();
+  }
+
+}
+
+#endif // I2C_SCANNER

Marlin/src/gcode/gcode.cpp

@@ -826,6 +826,10 @@ void GcodeSuite::process_parsed_command(bool no_ok/*=false*/) {
         case 261: M261(); break;                                  // M261: Request data from an i2c slave
       #endif
 
+      #if ENABLED(I2C_SCANNER)
+        case 265: M265(); break;                                  // M265: I2C Scanner
+      #endif
+
       #if ENABLED(PREVENT_COLD_EXTRUSION)
         case 302: M302(); break;                                  // M302: Allow cold extrudes (set the minimum extrude temperature)
       #endif

Marlin/src/gcode/gcode.h

@@ -211,6 +211,7 @@
  * M256 - Set LCD brightness: 'M256 B<brightness>' (0-255). (Requires an LCD with brightness control)
  * M260 - i2c Send Data (Requires EXPERIMENTAL_I2CBUS)
  * M261 - i2c Request Data (Requires EXPERIMENTAL_I2CBUS)
+ * M265 - i2c Scanner - Scan for I2C devices. (Requires I2C_SCANNER)
  * M280 - Set servo position absolute: 'M280 P<index> S<angle|µs>'. (Requires servos)
  * M281 - Set servo min|max position: 'M281 P<index> L<min> U<max>'. (Requires EDITABLE_SERVO_ANGLES)
  * M282 - Detach servo: 'M282 P<index>'. (Requires SERVO_DETACH_GCODE)
@@ -965,6 +966,10 @@ private:
     static void M261();
   #endif
 
+  #if ENABLED(I2C_SCANNER)
+    static void M265();
+  #endif
+
   #if HAS_SERVOS
     static void M280();
     #if ENABLED(EDITABLE_SERVO_ANGLES)

Marlin/src/inc/Conditionals-5-post.h

@@ -3651,7 +3651,7 @@
 #endif
 
 // Flag whether hex_print.cpp is needed
-#if ANY(AUTO_BED_LEVELING_UBL, M100_FREE_MEMORY_WATCHER, DEBUG_GCODE_PARSER, TMC_DEBUG, MARLIN_DEV_MODE, DEBUG_CARDREADER, M20_TIMESTAMP_SUPPORT, HAS_STM32_UID)
+#if ANY(AUTO_BED_LEVELING_UBL, M100_FREE_MEMORY_WATCHER, DEBUG_GCODE_PARSER, TMC_DEBUG, MARLIN_DEV_MODE, DEBUG_CARDREADER, M20_TIMESTAMP_SUPPORT, HAS_STM32_UID, I2C_SCANNER)
   #define NEED_HEX_PRINT 1
 #endif
 

buildroot/tests/DUE

@@ -39,7 +39,7 @@ exec_test $1 $2 "RAMPS4DUE_EFB with ABL (Bilinear), ExtUI, S-Curve, many options
 restore_configs
 opt_set MOTHERBOARD BOARD_RADDS Z_DRIVER_TYPE A4988 Z2_DRIVER_TYPE A4988 Z3_DRIVER_TYPE A4988 \
         X_MAX_PIN -1 Y_MAX_PIN -1
-opt_enable ENDSTOPPULLUPS BLTOUCH AUTO_BED_LEVELING_BILINEAR \
+opt_enable ENDSTOPPULLUPS BLTOUCH AUTO_BED_LEVELING_BILINEAR I2C_SCANNER \
            Z_STEPPER_AUTO_ALIGN Z_STEPPER_ALIGN_STEPPER_XY Z_SAFE_HOMING
 exec_test $1 $2 "RADDS with ABL (Bilinear), Triple Z Axis, Z_STEPPER_AUTO_ALIGN, E_DUAL_STEPPER_DRIVERS" "$3"
 

ini/features.ini

@@ -268,7 +268,8 @@ HAS_FILAMENT_SENSOR                    = build_src_filter=+<src/feature/runout.c
 MK2_MULTIPLEXER                        = build_src_filter=+<src/feature/snmm.cpp>
 HAS_CUTTER                             = build_src_filter=+<src/feature/spindle_laser.cpp> +<src/gcode/control/M3-M5.cpp>
 HAS_DRIVER_SAFE_POWER_PROTECT          = build_src_filter=+<src/feature/stepper_driver_safety.cpp>
-EXPERIMENTAL_I2CBUS                    = build_src_filter=+<src/feature/twibus.cpp> +<src/gcode/feature/i2c>
+EXPERIMENTAL_I2CBUS                    = build_src_filter=+<src/feature/twibus.cpp> +<src/gcode/feature/i2c/M260_M261.cpp>
+I2C_SCANNER                            = build_src_filter=+<src/gcode/feature/i2c/M265.cpp>
 G26_MESH_VALIDATION                    = build_src_filter=+<src/gcode/bedlevel/G26.cpp>
 ASSISTED_TRAMMING                      = build_src_filter=+<src/feature/tramming.cpp> +<src/gcode/bedlevel/G35.cpp>
 HAS_MESH                               = build_src_filter=+<src/gcode/bedlevel/G42.cpp>