stm32 PWM polarity via SIMPLEFOC_PWM_ACTIVE_HIGH

Author: Richard Unger

src/drivers/hardware_api.h

@@ -6,6 +6,27 @@
 #include "../communication/SimpleFOCDebug.h"
 
 
+// these defines determine the polarity of the PWM output. Normally, the polarity is active-high,
+// i.e. a high-level PWM output is expected to switch on the MOSFET. But should your driver design
+// require inverted polarity, you can change the defines below, or set them via your build environment
+// or board definition files.
+
+// used for 1-PWM, 2-PWM, 3-PWM, and 4-PWM modes
+#ifndef SIMPLEFOC_PWM_ACTIVE_HIGH
+#define SIMPLEFOC_PWM_ACTIVE_HIGH true
+#endif
+// used for 6-PWM mode, high-side
+#ifndef SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH
+#define SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH true
+#endif
+// used for 6-PWM mode, low-side
+#ifndef SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH
+#define SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH true
+#endif
+
+
+
+
 // flag returned if driver init fails
 #define SIMPLEFOC_DRIVER_INIT_FAILED ((void*)-1)
 

src/drivers/hardware_specific/rp2040_mcu.cpp

@@ -9,24 +9,6 @@
 #include "../hardware_api.h"
 #include "./rp2040_mcu.h"
 
-// these defines determine the polarity of the PWM output. Normally, the polarity is active-high,
-// i.e. a high-level PWM output is expected to switch on the MOSFET. But should your driver design
-// require inverted polarity, you can change the defines below, or set them via your build environment
-// or board definition files.
-
-// used for 2-PWM, 3-PWM, and 4-PWM modes
-#ifndef SIMPLEFOC_PWM_ACTIVE_HIGH
-#define SIMPLEFOC_PWM_ACTIVE_HIGH true
-#endif
-// used fof 6-PWM mode, high-side
-#ifndef SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH
-#define SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH true
-#endif
-// used fof 6-PWM mode, low-side
-#ifndef SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH
-#define SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH true
-#endif
-
 
 #define _PWM_FREQUENCY 24000
 #define _PWM_FREQUENCY_MAX 66000

src/drivers/hardware_specific/stm32_mcu.cpp

@@ -41,6 +41,34 @@ void _setPwm(HardwareTimer *HT, uint32_t channel, uint32_t value, int resolution
 
 
 
+int getLLChannel(PinMap* timer) {
+#if defined(TIM_CCER_CC1NE)
+  if (STM_PIN_INVERTED(timer->function)) {
+    switch (STM_PIN_CHANNEL(timer->function)) {
+      case 1: return LL_TIM_CHANNEL_CH1N;
+      case 2: return LL_TIM_CHANNEL_CH2N;
+      case 3: return LL_TIM_CHANNEL_CH3N;
+#if defined(LL_TIM_CHANNEL_CH4N)
+      case 4: return LL_TIM_CHANNEL_CH4N;
+#endif
+      default: return -1;
+    }
+  } else
+#endif
+  {
+    switch (STM_PIN_CHANNEL(timer->function)) {
+      case 1: return LL_TIM_CHANNEL_CH1;
+      case 2: return LL_TIM_CHANNEL_CH2;
+      case 3: return LL_TIM_CHANNEL_CH3;
+      case 4: return LL_TIM_CHANNEL_CH4;
+      default: return -1;
+    }
+  }
+  return -1;
+}
+
+
+
 
 
 // init pin pwm
@@ -63,6 +91,9 @@ HardwareTimer* _initPinPWM(uint32_t PWM_freq, PinMap* timer) {
   if (init)
     HT->setOverflow(PWM_freq, HERTZ_FORMAT);
   HT->setMode(channel, TIMER_OUTPUT_COMPARE_PWM1, timer->pin);
+  #if SIMPLEFOC_PWM_ACTIVE_HIGH==false
+  LL_TIM_OC_SetPolarity(HT->getHandle()->Instance, getLLChannel(timer), LL_TIM_OCPOLARITY_LOW);
+  #endif
 #ifdef SIMPLEFOC_STM32_DEBUG
   SIMPLEFOC_DEBUG("STM32-DRV: Configuring high timer ", (int)getTimerNumber(get_timer_index(HardwareTimer_Handle[index]->handle.Instance)));
   SIMPLEFOC_DEBUG("STM32-DRV: Configuring high channel ", (int)channel);
@@ -78,7 +109,11 @@ HardwareTimer* _initPinPWM(uint32_t PWM_freq, PinMap* timer) {
 
 // init high side pin
 HardwareTimer* _initPinPWMHigh(uint32_t PWM_freq, PinMap* timer) {
-  return _initPinPWM(PWM_freq, timer);
+  HardwareTimer* HT = _initPinPWM(PWM_freq, timer);
+  #if SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH==false && SIMPLEFOC_PWM_ACTIVE_HIGH==true
+  LL_TIM_OC_SetPolarity(HT->getHandle()->Instance, getLLChannel(timer), LL_TIM_OCPOLARITY_LOW);
+  #endif
+  return HT;
 }
 
 // init low side pin
@@ -107,6 +142,9 @@ HardwareTimer* _initPinPWMLow(uint32_t PWM_freq, PinMap* timer)
     HT->setOverflow(PWM_freq, HERTZ_FORMAT);
   // sets internal fields of HT, but we can't set polarity here
   HT->setMode(channel, TIMER_OUTPUT_COMPARE_PWM2, timer->pin);
+  #if SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH==false
+  LL_TIM_OC_SetPolarity(HT->getHandle()->Instance, getLLChannel(timer), LL_TIM_OCPOLARITY_LOW);
+  #endif
   return HT;
 }
 
@@ -213,34 +251,6 @@ void _alignTimersNew() {
 
 
 
-int getLLChannel(PinMap* timer) {
-#if defined(TIM_CCER_CC1NE)
-  if (STM_PIN_INVERTED(timer->function)) {
-    switch (STM_PIN_CHANNEL(timer->function)) {
-      case 1: return LL_TIM_CHANNEL_CH1N;
-      case 2: return LL_TIM_CHANNEL_CH2N;
-      case 3: return LL_TIM_CHANNEL_CH3N;
-#if defined(LL_TIM_CHANNEL_CH4N)
-      case 4: return LL_TIM_CHANNEL_CH4N;
-#endif
-      default: return -1;
-    }
-  } else
-#endif
-  {
-    switch (STM_PIN_CHANNEL(timer->function)) {
-      case 1: return LL_TIM_CHANNEL_CH1;
-      case 2: return LL_TIM_CHANNEL_CH2;
-      case 3: return LL_TIM_CHANNEL_CH3;
-      case 4: return LL_TIM_CHANNEL_CH4;
-      default: return -1;
-    }
-  }
-  return -1;
-}
-
-
-
 
 // configure hardware 6pwm for a complementary pair of channels
 STM32DriverParams* _initHardware6PWMPair(long PWM_freq, float dead_zone, PinMap* pinH, PinMap* pinL, STM32DriverParams* params, int paramsPos) {
@@ -278,8 +288,13 @@ STM32DriverParams* _initHardware6PWMPair(long PWM_freq, float dead_zone, PinMap*
   uint32_t dead_time_ns = (float)(1e9f/PWM_freq)*dead_zone;
   uint32_t dead_time = __LL_TIM_CALC_DEADTIME(SystemCoreClock, LL_TIM_GetClockDivision(HT->getHandle()->Instance), dead_time_ns);
   LL_TIM_OC_SetDeadTime(HT->getHandle()->Instance, dead_time); // deadtime is non linear!
+  #if SIMPLEFOC_PWM_HIGHSIDE_ACTIVE_HIGH==false
+  LL_TIM_OC_SetPolarity(HT->getHandle()->Instance, getLLChannel(pinH), LL_TIM_OCPOLARITY_LOW);
+  #endif
+  #if SIMPLEFOC_PWM_LOWSIDE_ACTIVE_HIGH==false
+  LL_TIM_OC_SetPolarity(HT->getHandle()->Instance, getLLChannel(pinL), LL_TIM_OCPOLARITY_LOW);
+  #endif
   LL_TIM_CC_EnableChannel(HT->getHandle()->Instance, getLLChannel(pinH) | getLLChannel(pinL));
-
   HT->pause();
 
   params->timers[paramsPos] = HT;