diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index e6ce386ef27..cb7ec8696e2 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -73,6 +73,9 @@
*
* M0 - Unconditional stop - Wait for user to press a button on the LCD (Only if ULTRA_LCD is enabled)
* M1 - Same as M0
+ * M3 - Turn laser/spindle on, set spindle/laser speed/power, set rotation to clockwise
+ * M4 - Turn laser/spindle on, set spindle/laser speed/power, set rotation to counter-clockwise
+ * M5 - Turn laser/spindle off
* M17 - Enable/Power all stepper motors
* M18 - Disable all stepper motors; same as M84
* M20 - List SD card. (Requires SDSUPPORT)
@@ -5611,6 +5614,121 @@ inline void gcode_G92() {
#endif // HAS_RESUME_CONTINUE
+#if ENABLED(SPINDLE_LASER_ENABLE)
+ /**
+ * M3: Spindle Clockwise
+ * M4: Spindle Counter-clockwise
+ *
+ * S0 turns off spindle.
+ *
+ * If no speed PWM output is defined then M3/M4 just turns it on.
+ *
+ * At least 12.8KHz (50Hz * 256) is needed for spindle PWM.
+ * Hardware PWM is required. ISRs are too slow.
+ *
+ * NOTE: WGM for timers 3, 4, and 5 must be either Mode 1 or Mode 5.
+ * No other settings give a PWM signal that goes from 0 to 5 volts.
+ *
+ * The system automatically sets WGM to Mode 1, so no special
+ * initialization is needed.
+ *
+ * WGM bits for timer 2 are automatically set by the system to
+ * Mode 1. This produces an acceptable 0 to 5 volt signal.
+ * No special initialization is needed.
+ *
+ * NOTE: A minimum PWM frequency of 50 Hz is needed. All prescaler
+ * factors for timers 2, 3, 4, and 5 are acceptable.
+ *
+ * SPINDLE_LASER_ENABLE_PIN needs an external pullup or it may power on
+ * the spindle/laser during power-up or when connecting to the host
+ * (usually goes through a reset which sets all I/O pins to tri-state)
+ *
+ * PWM duty cycle goes from 0 (off) to 255 (always on).
+ */
+
+ // Wait for spindle to come up to speed
+ inline void delay_for_power_up() {
+ refresh_cmd_timeout();
+ while (PENDING(millis(), SPINDLE_LASER_POWERUP_DELAY + previous_cmd_ms)) idle();
+ }
+
+ // Wait for spindle to stop turning
+ inline void delay_for_power_down() {
+ refresh_cmd_timeout();
+ while (PENDING(millis(), SPINDLE_LASER_POWERDOWN_DELAY + previous_cmd_ms + 1)) idle();
+ }
+
+ /**
+ * ocr_val_mode() is used for debugging and to get the points needed to compute the RPM vs ocr_val line
+ *
+ * it accepts inputs of 0-255
+ */
+
+ inline void ocr_val_mode() {
+ uint8_t spindle_laser_power = code_value_byte();
+ WRITE(SPINDLE_LASER_ENABLE_PIN, SPINDLE_LASER_ENABLE_INVERT); // turn spindle on (active low)
+ if (SPINDLE_LASER_PWM_INVERT) spindle_laser_power = 255 - spindle_laser_power;
+ analogWrite(SPINDLE_LASER_PWM_PIN, spindle_laser_power);
+ }
+
+ inline void gcode_M3_M4(bool is_M3) {
+
+ stepper.synchronize(); // wait until previous movement commands (G0/G0/G2/G3) have completed before playing with the spindle
+ #if SPINDLE_DIR_CHANGE
+ const bool rotation_dir = (is_M3 && !SPINDLE_INVERT_DIR || !is_M3 && SPINDLE_INVERT_DIR) ? HIGH : LOW;
+ if (SPINDLE_STOP_ON_DIR_CHANGE \
+ && READ(SPINDLE_LASER_ENABLE_PIN) == SPINDLE_LASER_ENABLE_INVERT \
+ && READ(SPINDLE_DIR_PIN) != rotation_dir
+ ) {
+ WRITE(SPINDLE_LASER_ENABLE_PIN, !SPINDLE_LASER_ENABLE_INVERT); // turn spindle off
+ delay_for_power_down();
+ }
+ digitalWrite(SPINDLE_DIR_PIN, rotation_dir);
+ #endif
+
+ /**
+ * Our final value for ocr_val is an unsigned 8 bit value between 0 and 255 which usually means uint8_t.
+ * Went to uint16_t because some of the uint8_t calculations would sometimes give 1000 0000 rather than 1111 1111.
+ * Then needed to AND the uint16_t result with 0x00FF to make sure we only wrote the byte of interest.
+ */
+ #if ENABLED(SPINDLE_LASER_PWM)
+ if (code_seen('O')) ocr_val_mode();
+ else {
+ const float spindle_laser_power = code_seen('S') ? code_value_float() : 0;
+ if (spindle_laser_power == 0) {
+ WRITE(SPINDLE_LASER_ENABLE_PIN, !SPINDLE_LASER_ENABLE_INVERT); // turn spindle off (active low)
+ delay_for_power_down();
+ }
+ else {
+ int16_t ocr_val = (spindle_laser_power - (SPEED_POWER_INTERCEPT)) * (1.0 / (SPEED_POWER_SLOPE)); // convert RPM to PWM duty cycle
+ NOMORE(ocr_val, 255); // limit to max the Atmel PWM will support
+ if (spindle_laser_power <= SPEED_POWER_MIN)
+ ocr_val = (SPEED_POWER_MIN - (SPEED_POWER_INTERCEPT)) * (1.0 / (SPEED_POWER_SLOPE)); // minimum setting
+ if (spindle_laser_power >= SPEED_POWER_MAX)
+ ocr_val = (SPEED_POWER_MAX - (SPEED_POWER_INTERCEPT)) * (1.0 / (SPEED_POWER_SLOPE)); // limit to max RPM
+ if (SPINDLE_LASER_PWM_INVERT) ocr_val = 255 - ocr_val;
+ WRITE(SPINDLE_LASER_ENABLE_PIN, SPINDLE_LASER_ENABLE_INVERT); // turn spindle on (active low)
+ analogWrite(SPINDLE_LASER_PWM_PIN, ocr_val & 0xFF); // only write low byte
+ delay_for_power_up();
+ }
+ }
+ #else
+ WRITE(SPINDLE_LASER_ENABLE_PIN, SPINDLE_LASER_ENABLE_INVERT); // turn spindle on (active low) if spindle speed option not enabled
+ delay_for_power_up();
+ #endif
+ }
+
+ /**
+ * M5 turn off spindle
+ */
+ inline void gcode_M5() {
+ stepper.synchronize();
+ WRITE(SPINDLE_LASER_ENABLE_PIN, !SPINDLE_LASER_ENABLE_INVERT);
+ delay_for_power_down();
+ }
+
+#endif // SPINDLE_LASER_ENABLE
+
/**
* M17: Enable power on all stepper motors
*/
@@ -5626,6 +5744,7 @@ inline void gcode_M17() {
#endif
#if ENABLED(PARK_HEAD_ON_PAUSE)
+
float resume_position[XYZE];
bool move_away_flag = false;
@@ -9946,6 +10065,17 @@ void process_next_command() {
break;
#endif // ULTIPANEL
+ #if ENABLED(SPINDLE_LASER_ENABLE)
+ case 3:
+ gcode_M3_M4(true); // M3: turn spindle/laser on, set laser/spindle power/speed, set rotation direction CW
+ break; // synchronizes with movement commands
+ case 4:
+ gcode_M3_M4(false); // M4: turn spindle/laser on, set laser/spindle power/speed, set rotation direction CCW
+ break; // synchronizes with movement commands
+ case 5:
+ gcode_M5(); // M5 - turn spindle/laser off
+ break; // synchronizes with movement commands
+ #endif
case 17: // M17: Enable all stepper motors
gcode_M17();
break;
@@ -12262,6 +12392,17 @@ void setup() {
update_case_light();
#endif
+ #if ENABLED(SPINDLE_LASER_ENABLE)
+ OUT_WRITE(SPINDLE_LASER_ENABLE_PIN, !SPINDLE_LASER_ENABLE_INVERT); // init spindle to off
+ #if SPINDLE_DIR_CHANGE
+ OUT_WRITE(SPINDLE_DIR_PIN, SPINDLE_INVERT_DIR ? 255 : 0); // init rotation to clockwise (M3)
+ #endif
+ #if ENABLED(SPINDLE_LASER_PWM)
+ SET_OUTPUT(SPINDLE_LASER_PWM_PIN);
+ analogWrite(SPINDLE_LASER_PWM_PIN, SPINDLE_LASER_PWM_INVERT ? 255 : 0); // set to lowest speed
+ #endif
+ #endif
+
#if HAS_BED_PROBE
endstops.enable_z_probe(false);
#endif