⚗️ Use pwm_set_duty over analogWrite to set PWM (#23048)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

Marlin/src/HAL/AVR/HAL.h

@@ -221,7 +221,7 @@ void set_pwm_frequency(const pin_t pin, int f_desired);
 
 /**
  * set_pwm_duty
- *  Sets the PWM duty cycle of the provided pin to the provided value
+ *  Set the PWM duty cycle of the provided pin to the provided value
  *  Optionally allows inverting the duty cycle [default = false]
  *  Optionally allows changing the maximum size of the provided value to enable finer PWM duty control [default = 255]
  */

Marlin/src/HAL/AVR/fast_pwm.cpp

@@ -22,11 +22,10 @@
 #ifdef __AVR__
 
 #include "../../inc/MarlinConfigPre.h"
+#include "HAL.h"
 
 #if NEEDS_HARDWARE_PWM // Specific meta-flag for features that mandate PWM
 
-#include "HAL.h"
-
 struct Timer {
   volatile uint8_t* TCCRnQ[3];  // max 3 TCCR registers per timer
   volatile uint16_t* OCRnQ[3];  // max 3 OCR registers per timer
@@ -153,7 +152,7 @@ Timer get_pwm_timer(const pin_t pin) {
 
 void set_pwm_frequency(const pin_t pin, int f_desired) {
   Timer timer = get_pwm_timer(pin);
-  if (timer.n == 0) return; // Don't proceed if protected timer or not recognised
+  if (timer.n == 0) return; // Don't proceed if protected timer or not recognized
   uint16_t size;
   if (timer.n == 2) size = 255; else size = 65535;
 
@@ -243,7 +242,11 @@ void set_pwm_frequency(const pin_t pin, int f_desired) {
     _SET_ICRn(timer.ICRn, res);         // Set ICRn value (TOP) = res
 }
 
+#endif // NEEDS_HARDWARE_PWM
+
 void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
+  #if NEEDS_HARDWARE_PWM
+
     // If v is 0 or v_size (max), digitalWrite to LOW or HIGH.
     // Note that digitalWrite also disables pwm output for us (sets COM bit to 0)
     if (v == 0)
@@ -252,7 +255,7 @@ void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255
       digitalWrite(pin, !invert);
     else {
       Timer timer = get_pwm_timer(pin);
-    if (timer.n == 0) return; // Don't proceed if protected timer or not recognised
+      if (timer.n == 0) return; // Don't proceed if protected timer or not recognized
       // Set compare output mode to CLEAR -> SET or SET -> CLEAR (if inverted)
       _SET_COMnQ(timer.TCCRnQ, (timer.q
           #ifdef TCCR2
@@ -261,22 +264,17 @@ void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255
         ), COM_CLEAR_SET + invert
       );
 
-    uint16_t top;
-    if (timer.n == 2) { // if TIMER2
-      top = (
-        #if ENABLED(USE_OCR2A_AS_TOP)
-          *timer.OCRnQ[0] // top = OCR2A
-        #else
-          255 // top = 0xFF (max)
-        #endif
-      );
+      uint16_t top = (timer.n == 2) ? TERN(USE_OCR2A_AS_TOP, *timer.OCRnQ[0], 255) : *timer.ICRn;
+      _SET_OCRnQ(timer.OCRnQ, timer.q, (v * top + v_size / 2) / v_size); // Scale 8/16-bit v to top value
     }
-    else
-      top = *timer.ICRn; // top = ICRn
 
-    _SET_OCRnQ(timer.OCRnQ, timer.q, v * float(top) / float(v_size)); // Scale 8/16-bit v to top value
-  }
+  #else
+
+    analogWrite(pin, v);
+    UNUSED(v_size);
+    UNUSED(invert);
+
+  #endif
 }
 
-#endif // NEEDS_HARDWARE_PWM
 #endif // __AVR__

Marlin/src/HAL/DUE/HAL.h

@@ -144,6 +144,11 @@ inline void HAL_adc_init() {}//todo
 void HAL_adc_start_conversion(const uint8_t ch);
 uint16_t HAL_adc_get_result();
 
+//
+// PWM
+//
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
 //
 // Pin Map
 //

Marlin/src/HAL/ESP32/HAL.h

@@ -129,6 +129,10 @@ void HAL_adc_init();
 
 void HAL_adc_start_conversion(const uint8_t adc_pin);
 
+// PWM
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
+// Pin Map
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)

Marlin/src/HAL/LINUX/HAL.h

@@ -101,6 +101,9 @@ void HAL_adc_enable_channel(const uint8_t ch);
 void HAL_adc_start_conversion(const uint8_t ch);
 uint16_t HAL_adc_get_result();
 
+// PWM
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
 // Reset source
 inline void HAL_clear_reset_source(void) {}
 inline uint8_t HAL_get_reset_source(void) { return RST_POWER_ON; }

Marlin/src/HAL/LPC1768/fast_pwm.cpp

@@ -22,18 +22,18 @@
 #ifdef TARGET_LPC1768
 
 #include "../../inc/MarlinConfigPre.h"
-
-#if NEEDS_HARDWARE_PWM // Specific meta-flag for features that mandate PWM
-
 #include <pwm.h>
 
-void set_pwm_frequency(const pin_t pin, int f_desired) {
-  LPC176x::pwm_set_frequency(pin, f_desired);
-}
-
 void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
   LPC176x::pwm_write_ratio(pin, invert ? 1.0f - (float)v / v_size : (float)v / v_size);
 }
 
-#endif // NEEDS_HARDWARE_PWM
+#if NEEDS_HARDWARE_PWM // Specific meta-flag for features that mandate PWM
+
+  void set_pwm_frequency(const pin_t pin, int f_desired) {
+    LPC176x::pwm_set_frequency(pin, f_desired);
+  }
+
+#endif
+
 #endif // TARGET_LPC1768

Marlin/src/HAL/NATIVE_SIM/HAL.h

@@ -133,6 +133,9 @@ void HAL_adc_enable_channel(const uint8_t ch);
 void HAL_adc_start_conversion(const uint8_t ch);
 uint16_t HAL_adc_get_result();
 
+// PWM
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
 // Reset source
 inline void HAL_clear_reset_source(void) {}
 inline uint8_t HAL_get_reset_source(void) { return RST_POWER_ON; }

Marlin/src/HAL/SAMD51/HAL.h

@@ -127,6 +127,11 @@ void HAL_adc_init();
 
 void HAL_adc_start_conversion(const uint8_t adc_pin);
 
+//
+// PWM
+//
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
 //
 // Pin Map
 //

Marlin/src/HAL/STM32/fast_pwm.cpp

@@ -24,26 +24,9 @@
 
 #ifdef HAL_STM32
 
-#include "../../inc/MarlinConfigPre.h"
-
-#if NEEDS_HARDWARE_PWM
-
-#include "HAL.h"
+#include "../../inc/MarlinConfig.h"
 #include "timers.h"
 
-void set_pwm_frequency(const pin_t pin, int f_desired) {
-  if (!PWM_PIN(pin)) return;            // Don't proceed if no hardware timer
-
-  PinName pin_name = digitalPinToPinName(pin);
-  TIM_TypeDef *Instance = (TIM_TypeDef *)pinmap_peripheral(pin_name, PinMap_PWM); // Get HAL timer instance
-
-  LOOP_S_L_N(i, 0, NUM_HARDWARE_TIMERS) // Protect used timers
-    if (timer_instance[i] && timer_instance[i]->getHandle()->Instance == Instance)
-      return;
-
-  pwm_start(pin_name, f_desired, 0, RESOLUTION_8B_COMPARE_FORMAT);
-}
-
 void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
   PinName pin_name = digitalPinToPinName(pin);
   TIM_TypeDef *Instance = (TIM_TypeDef *)pinmap_peripheral(pin_name, PinMap_PWM);
@@ -58,5 +41,21 @@ void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255
   }
 }
 
-#endif // NEEDS_HARDWARE_PWM
+#if NEEDS_HARDWARE_PWM
+
+  void set_pwm_frequency(const pin_t pin, int f_desired) {
+    if (!PWM_PIN(pin)) return;            // Don't proceed if no hardware timer
+
+    PinName pin_name = digitalPinToPinName(pin);
+    TIM_TypeDef *Instance = (TIM_TypeDef *)pinmap_peripheral(pin_name, PinMap_PWM); // Get HAL timer instance
+
+    LOOP_S_L_N(i, 0, NUM_HARDWARE_TIMERS) // Protect used timers
+      if (timer_instance[i] && timer_instance[i]->getHandle()->Instance == Instance)
+        return;
+
+    pwm_start(pin_name, f_desired, 0, RESOLUTION_8B_COMPARE_FORMAT);
+  }
+
+#endif
+
 #endif // HAL_STM32

Marlin/src/HAL/STM32F1/HAL.cpp

@@ -449,8 +449,7 @@ uint16_t analogRead(pin_t pin) {
 
 // Wrapper to maple unprotected analogWrite
 void analogWrite(pin_t pin, int pwm_val8) {
-  if (PWM_PIN(pin))
-    analogWrite(uint8_t(pin), pwm_val8);
+  if (PWM_PIN(pin)) analogWrite(uint8_t(pin), pwm_val8);
 }
 
 void HAL_reboot() { nvic_sys_reset(); }

Marlin/src/HAL/STM32F1/fast_pwm.cpp

@@ -23,13 +23,20 @@
 
 #include "../../inc/MarlinConfigPre.h"
 
-#if NEEDS_HARDWARE_PWM
-
 #include <pwm.h>
 #include "HAL.h"
 #include "timers.h"
 
-void set_pwm_frequency(const pin_t pin, int f_desired) {
+void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
+  timer_dev *timer = PIN_MAP[pin].timer_device;
+  uint16_t max_val = timer->regs.bas->ARR * v / v_size;
+  if (invert) max_val = v_size - max_val;
+  pwmWrite(pin, max_val);
+}
+
+#if NEEDS_HARDWARE_PWM
+
+  void set_pwm_frequency(const pin_t pin, int f_desired) {
     if (!PWM_PIN(pin)) return;                    // Don't proceed if no hardware timer
 
     timer_dev *timer = PIN_MAP[pin].timer_device;
@@ -55,14 +62,7 @@ void set_pwm_frequency(const pin_t pin, int f_desired) {
     if (prescaler < 0) return;                    // Too high frequency
     timer_set_reload(timer, preload);
     timer_set_prescaler(timer, prescaler);
-}
-
-void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
-  timer_dev *timer = PIN_MAP[pin].timer_device;
-  uint16_t max_val = timer->regs.bas->ARR * v / v_size;
-  if (invert) max_val = v_size - max_val;
-  pwmWrite(pin, max_val);
-}
+  }
 
 #endif // NEEDS_HARDWARE_PWM
 #endif // __STM32F1__

Marlin/src/HAL/TEENSY31_32/HAL.h

@@ -122,6 +122,12 @@ void HAL_adc_init();
 void HAL_adc_start_conversion(const uint8_t adc_pin);
 uint16_t HAL_adc_get_result();
 
+// PWM
+
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
+// Pin Map
+
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)

Marlin/src/HAL/TEENSY35_36/HAL.h

@@ -129,6 +129,12 @@ void HAL_adc_init();
 void HAL_adc_start_conversion(const uint8_t adc_pin);
 uint16_t HAL_adc_get_result();
 
+// PWM
+
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
+// Pin Map
+
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)

Marlin/src/HAL/TEENSY40_41/HAL.cpp

@@ -106,17 +106,17 @@ void HAL_adc_init() {
 void HAL_clear_reset_source() {
   uint32_t reset_source = SRC_SRSR;
   SRC_SRSR = reset_source;
- }
+}
 
 uint8_t HAL_get_reset_source() {
   switch (SRC_SRSR & 0xFF) {
     case 1: return RST_POWER_ON; break;
     case 2: return RST_SOFTWARE; break;
     case 4: return RST_EXTERNAL; break;
-    // case 8: return RST_BROWN_OUT; break;
+    //case 8: return RST_BROWN_OUT; break;
     case 16: return RST_WATCHDOG; break;
     case 64: return RST_JTAG; break;
-    // case 128: return RST_OVERTEMP; break;
+    //case 128: return RST_OVERTEMP; break;
   }
   return 0;
 }
@@ -168,7 +168,7 @@ uint16_t HAL_adc_get_result() {
   return 0;
 }
 
-bool is_output(uint8_t pin) {
+bool is_output(pin_t pin) {
   const struct digital_pin_bitband_and_config_table_struct *p;
   p = digital_pin_to_info_PGM + pin;
   return (*(p->reg + 1) & p->mask);

Marlin/src/HAL/TEENSY40_41/HAL.h

@@ -150,8 +150,14 @@ void HAL_adc_init();
 void HAL_adc_start_conversion(const uint8_t adc_pin);
 uint16_t HAL_adc_get_result();
 
+// PWM
+
+inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+
+// Pin Map
+
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)
 
-bool is_output(uint8_t pin);
+bool is_output(pin_t pin);

Marlin/src/feature/caselight.cpp

@@ -70,7 +70,7 @@ void CaseLight::update(const bool sflag) {
 
     #if CASELIGHT_USES_BRIGHTNESS
       if (pin_is_pwm())
-        analogWrite(pin_t(CASE_LIGHT_PIN), (
+        set_pwm_duty(pin_t(CASE_LIGHT_PIN), (
           #if CASE_LIGHT_MAX_PWM == 255
             n10ct
           #else

Marlin/src/feature/controllerfan.cpp

@@ -72,9 +72,10 @@ void ControllerFan::update() {
       ? settings.active_speed : settings.idle_speed
     );
 
-    // Allow digital or PWM fan output (see M42 handling)
+    if (PWM_PIN(CONTROLLER_FAN_PIN))
+      set_pwm_duty(pin_t(CONTROLLER_FAN_PIN), speed);
+    else
       WRITE(CONTROLLER_FAN_PIN, speed);
-    analogWrite(pin_t(CONTROLLER_FAN_PIN), speed);
   }
 }
 

Marlin/src/feature/leds/leds.cpp

@@ -123,7 +123,7 @@ void LEDLights::set_color(const LEDColor &incol
     // If the pins can do PWM then their intensity will be set.
     #define _UPDATE_RGBW(C,c) do {                 \
       if (PWM_PIN(RGB_LED_##C##_PIN))              \
-        analogWrite(pin_t(RGB_LED_##C##_PIN), c); \
+        set_pwm_duty(pin_t(RGB_LED_##C##_PIN), c); \
       else                                         \
         WRITE(RGB_LED_##C##_PIN, c ? HIGH : LOW);  \
     }while(0)

Marlin/src/feature/spindle_laser.cpp

@@ -66,7 +66,7 @@ void SpindleLaser::init() {
   #endif
   #if ENABLED(SPINDLE_LASER_USE_PWM)
     SET_PWM(SPINDLE_LASER_PWM_PIN);
-    analogWrite(pin_t(SPINDLE_LASER_PWM_PIN), SPINDLE_LASER_PWM_OFF); // Set to lowest speed
+    set_pwm_duty(pin_t(SPINDLE_LASER_PWM_PIN), SPINDLE_LASER_PWM_OFF); // Set to lowest speed
   #endif
   #if ENABLED(HAL_CAN_SET_PWM_FREQ) && defined(SPINDLE_LASER_FREQUENCY)
     set_pwm_frequency(pin_t(SPINDLE_LASER_PWM_PIN), SPINDLE_LASER_FREQUENCY);
@@ -92,10 +92,8 @@ void SpindleLaser::init() {
   void SpindleLaser::_set_ocr(const uint8_t ocr) {
     #if NEEDS_HARDWARE_PWM && SPINDLE_LASER_FREQUENCY
       set_pwm_frequency(pin_t(SPINDLE_LASER_PWM_PIN), TERN(MARLIN_DEV_MODE, frequency, SPINDLE_LASER_FREQUENCY));
-      set_pwm_duty(pin_t(SPINDLE_LASER_PWM_PIN), ocr ^ SPINDLE_LASER_PWM_OFF);
-    #else
-      analogWrite(pin_t(SPINDLE_LASER_PWM_PIN), ocr ^ SPINDLE_LASER_PWM_OFF);
     #endif
+    set_pwm_duty(pin_t(SPINDLE_LASER_PWM_PIN), ocr ^ SPINDLE_LASER_PWM_OFF);
   }
 
   void SpindleLaser::set_ocr(const uint8_t ocr) {

Marlin/src/gcode/control/M42.cpp

@@ -126,10 +126,10 @@ void GcodeSuite::M42() {
   extDigitalWrite(pin, pin_status);
 
   #ifdef ARDUINO_ARCH_STM32
-    // A simple I/O will be set to 0 by analogWrite()
+    // A simple I/O will be set to 0 by set_pwm_duty()
     if (pin_status <= 1 && !PWM_PIN(pin)) return;
   #endif
-  analogWrite(pin, pin_status);
+  set_pwm_duty(pin, pin_status);
 }
 
 #endif // DIRECT_PIN_CONTROL

Marlin/src/lcd/dogm/marlinui_DOGM.cpp

@@ -342,7 +342,7 @@ void MarlinUI::clear_lcd() { } // Automatically cleared by Picture Loop
   void MarlinUI::_set_brightness() {
     #if PIN_EXISTS(TFT_BACKLIGHT)
       if (PWM_PIN(TFT_BACKLIGHT_PIN))
-        analogWrite(pin_t(TFT_BACKLIGHT_PIN), brightness);
+        set_pwm_duty(pin_t(TFT_BACKLIGHT_PIN), brightness);
     #endif
   }
 #endif

Marlin/src/lcd/tft/ui_common.cpp

@@ -213,7 +213,7 @@ void MarlinUI::clear_lcd() {
   void MarlinUI::_set_brightness() {
     #if PIN_EXISTS(TFT_BACKLIGHT)
       if (PWM_PIN(TFT_BACKLIGHT_PIN))
-        analogWrite(pin_t(TFT_BACKLIGHT_PIN), brightness);
+        set_pwm_duty(pin_t(TFT_BACKLIGHT_PIN), brightness);
     #endif
   }
 #endif

Marlin/src/module/endstops.cpp

@@ -1342,7 +1342,7 @@ void Endstops::update() {
         ES_REPORT_CHANGE(K_MAX);
       #endif
       SERIAL_ECHOLNPGM("\n");
-      analogWrite(pin_t(LED_PIN), local_LED_status);
+      set_pwm_duty(pin_t(LED_PIN), local_LED_status);
       local_LED_status ^= 255;
       old_live_state_local = live_state_local;
     }

Marlin/src/module/planner.cpp

@@ -1270,7 +1270,7 @@ void Planner::recalculate() {
     #elif ENABLED(FAST_PWM_FAN)
       #define _FAN_SET(F) set_pwm_duty(FAN##F##_PIN, CALC_FAN_SPEED(F));
     #else
-      #define _FAN_SET(F) analogWrite(pin_t(FAN##F##_PIN), CALC_FAN_SPEED(F));
+      #define _FAN_SET(F) set_pwm_duty(pin_t(FAN##F##_PIN), CALC_FAN_SPEED(F));
     #endif
     #define FAN_SET(F) do{ kickstart_fan(fan_speed, ms, F); _FAN_SET(F); }while(0)
 
@@ -1393,8 +1393,8 @@ void Planner::check_axes_activity() {
   TERN_(AUTOTEMP, autotemp_task());
 
   #if ENABLED(BARICUDA)
-    TERN_(HAS_HEATER_1, analogWrite(pin_t(HEATER_1_PIN), tail_valve_pressure));
-    TERN_(HAS_HEATER_2, analogWrite(pin_t(HEATER_2_PIN), tail_e_to_p_pressure));
+    TERN_(HAS_HEATER_1, set_pwm_duty(pin_t(HEATER_1_PIN), tail_valve_pressure));
+    TERN_(HAS_HEATER_2, set_pwm_duty(pin_t(HEATER_2_PIN), tail_e_to_p_pressure));
   #endif
 }
 

Marlin/src/module/stepper.cpp

@@ -3253,7 +3253,7 @@ void Stepper::report_positions() {
 
       #elif HAS_MOTOR_CURRENT_PWM
 
-        #define _WRITE_CURRENT_PWM(P) analogWrite(pin_t(MOTOR_CURRENT_PWM_## P ##_PIN), 255L * current / (MOTOR_CURRENT_PWM_RANGE))
+        #define _WRITE_CURRENT_PWM(P) set_pwm_duty(pin_t(MOTOR_CURRENT_PWM_## P ##_PIN), 255L * current / (MOTOR_CURRENT_PWM_RANGE))
         switch (driver) {
           case 0:
             #if PIN_EXISTS(MOTOR_CURRENT_PWM_X)

Marlin/src/module/temperature.cpp

@@ -889,7 +889,7 @@ int16_t Temperature::getHeaterPower(const heater_id_t heater_id) {
 
     #define _UPDATE_AUTO_FAN(P,D,A) do{                   \
       if (PWM_PIN(P##_AUTO_FAN_PIN) && A < 255)           \
-        analogWrite(pin_t(P##_AUTO_FAN_PIN), D ? A : 0); \
+        set_pwm_duty(pin_t(P##_AUTO_FAN_PIN), D ? A : 0); \
       else                                                \
         WRITE(P##_AUTO_FAN_PIN, D);                       \
     }while(0)