⚗️ Use pwm_set_duty over analogWrite to set PWM (MarlinFirmware#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;
 
@@ -243,40 +242,39 @@ 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 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)
-    digitalWrite(pin, invert);
-  else if (v == v_size)
-    digitalWrite(pin, !invert);
-  else {
-    Timer timer = get_pwm_timer(pin);
-    if (timer.n == 0) return; // Don't proceed if protected timer or not recognised
-    // Set compare output mode to CLEAR -> SET or SET -> CLEAR (if inverted)
-    _SET_COMnQ(timer.TCCRnQ, (timer.q
-        #ifdef TCCR2
-          + (timer.q == 2) // COM20 is on bit 4 of TCCR2, thus requires q + 1 in the macro
-        #endif
-      ), COM_CLEAR_SET + invert
-    );
+  #if NEEDS_HARDWARE_PWM
 
-    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
+    // 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)
+      digitalWrite(pin, invert);
+    else if (v == v_size)
+      digitalWrite(pin, !invert);
+    else {
+      Timer timer = get_pwm_timer(pin);
+      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
+            + (timer.q == 2) // COM20 is on bit 4 of TCCR2, thus requires q + 1 in the macro
+          #endif
+        ), COM_CLEAR_SET + invert
       );
+
+      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

@@ -23,46 +23,46 @@
 
 #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) {
-  if (!PWM_PIN(pin)) return;                    // Don't proceed if no hardware timer
-
-  timer_dev *timer = PIN_MAP[pin].timer_device;
-  uint8_t channel = PIN_MAP[pin].timer_channel;
-
-  // Protect used timers
-  if (timer == get_timer_dev(TEMP_TIMER_NUM)) return;
-  if (timer == get_timer_dev(STEP_TIMER_NUM)) return;
-  #if PULSE_TIMER_NUM != STEP_TIMER_NUM
-    if (timer == get_timer_dev(PULSE_TIMER_NUM)) return;
-  #endif
-
-  if (!(timer->regs.bas->SR & TIMER_CR1_CEN))   // Ensure the timer is enabled
-    timer_init(timer);
-
-  timer_set_mode(timer, channel, TIMER_PWM);
-  uint16_t preload = 255;                       // Lock 255 PWM resolution for high frequencies
-  int32_t prescaler = (HAL_TIMER_RATE) / (preload + 1) / f_desired - 1;
-  if (prescaler > 65535) {                      // For low frequencies increase prescaler
-    prescaler = 65535;
-    preload = (HAL_TIMER_RATE) / (prescaler + 1) / f_desired - 1;
-  }
-  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);
 }
 
+#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;
+    uint8_t channel = PIN_MAP[pin].timer_channel;
+
+    // Protect used timers
+    if (timer == get_timer_dev(TEMP_TIMER_NUM)) return;
+    if (timer == get_timer_dev(STEP_TIMER_NUM)) return;
+    #if PULSE_TIMER_NUM != STEP_TIMER_NUM
+      if (timer == get_timer_dev(PULSE_TIMER_NUM)) return;
+    #endif
+
+    if (!(timer->regs.bas->SR & TIMER_CR1_CEN))   // Ensure the timer is enabled
+      timer_init(timer);
+
+    timer_set_mode(timer, channel, TIMER_PWM);
+    uint16_t preload = 255;                       // Lock 255 PWM resolution for high frequencies
+    int32_t prescaler = (HAL_TIMER_RATE) / (preload + 1) / f_desired - 1;
+    if (prescaler > 65535) {                      // For low frequencies increase prescaler
+      prescaler = 65535;
+      preload = (HAL_TIMER_RATE) / (prescaler + 1) / f_desired - 1;
+    }
+    if (prescaler < 0) return;                    // Too high frequency
+    timer_set_reload(timer, preload);
+    timer_set_prescaler(timer, prescaler);
+  }
+
 #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 64: return RST_JTAG; 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);