STM32F103 PWM Interrupt not working (UPDATED)

[christiaan2]

Posted on August 06, 2015 at 09:43

Hi all

I have a problem. I am trying to update the PWM duty cycle using TIM1 update interrupt. In the interrupt I write values to the TIM1 CCR1, CCR2 and CCR3 registers. When I run the code nothing happens.Have I misconfigured the interrupt or is there something else wrong?Thank you for your time.Christiaan&sharpinclude ''stm32f10x.h''TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;TIM_OCInitTypeDef  TIM_OCInitStructure;TIM_BDTRInitTypeDef TIM_BDTRInitStructure;NVIC_InitTypeDef NVIC_InitStructure;int TimerPeriod = 0, n = 0;int Channel1Pulse = 0, Channel2Pulse = 0, Channel3Pulse = 0;uint16_t pulse_width = 0;void RCC_Configuration(void);void GPIO_Configuration(void);void TIM1_IRQHandler(void);void PWM_SetDC(uint16_t dutycycle);void Delay(__IO uint32_t nCount);int main(void){ /* System Clocks Configuration */ SystemInit(); RCC_Configuration();  /* GPIO Configuration */  GPIO_Configuration();  /* TIM1 Configuration --------------------------------------------------- */ /* Compute the value to be set in ARR regiter to generate signal frequency at 10 Khz */ TimerPeriod = (SystemCoreClock / 22500);  /* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */  Channel1Pulse = (TimerPeriod / 6);  /* Compute CCR2 value to generate a duty cycle at 50%  for channel 2 and 2N with 60 degree phase shift*/  Channel2Pulse = (TimerPeriod / 6) + (TimerPeriod / 3);  /* Compute CCR3 value to generate a duty cycle at 50%  for channel 3 and 3N with 120 degree phase shift*/  Channel3Pulse = (TimerPeriod / 6) + ((TimerPeriod * 2) / 3);  /* Interrupt configuration */  NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQn;  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  NVIC_Init(&NVIC_InitStructure); /* Time Base configuration */  TIM_TimeBaseStructure.TIM_Prescaler = 0;  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  TIM_TimeBaseStructure.TIM_Period = TimerPeriod - 1;  TIM_TimeBaseStructure.TIM_ClockDivision = 0;  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);  /* Channel 1, 2,3 and 4 Configuration in PWM mode */  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;  TIM_OCInitStructure.TIM_Pulse = Channel1Pulse; TIM_OC1Init(TIM1, &TIM_OCInitStructure);  TIM_OCInitStructure.TIM_Pulse = Channel2Pulse;  TIM_OC2Init(TIM1, &TIM_OCInitStructure);  TIM_OCInitStructure.TIM_Pulse = Channel3Pulse;  TIM_OC3Init(TIM1, &TIM_OCInitStructure);  /* Dead time configuration (3.7 us) */  TIM_BDTRInitStructure.TIM_DeadTime = 183;  TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure); /* TIM1 IT Enable */  TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE); /* TIM1 counter enable */  TIM_Cmd(TIM1, ENABLE);  /* TIM1 Main Output Enable */  TIM_CtrlPWMOutputs(TIM1, ENABLE);  while (1)  {     PWM_SetDC(pulse_width++);    if (pulse_width >= 200)    {      pulse_width = 0;    }    Delay(100);  }}void RCC_Configuration(void){  /* TIM1, GPIOA, GPIOB and AFIO clocks enable */  RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); RCC_APB2PeriphResetCmd(RCC_APB2Periph_TIM1,DISABLE);}/* Configure the TIM1 Pins. */void GPIO_Configuration(void){ GPIO_InitTypeDef GPIO_InitStructure;   /* GPIOA Configuration: Channel 1, 2 and 3 as alternate function push-pull */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_Init(GPIOA, &GPIO_InitStructure);  /* GPIOB Configuration: Channel 1N, 2N and 3N as alternate function push-pull */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;  GPIO_Init(GPIOB, &GPIO_InitStructure);}void TIM1_IRQHandler(void){  if (TIM_GetITStatus(TIM1, TIM_IT_Update) != RESET)  {    TIM_ClearITPendingBit(TIM1, TIM_IT_Update);  }}void PWM_SetDC(uint16_t dutycycle){    TIM1->CCR1 = dutycycle;    TIM1->CCR2 = dutycycle;    TIM1->CCR3 = dutycycle;}void Delay(__IO uint32_t nCount){  while(nCount--)  {  }} #tim1 #pwm #interrupt #stm32f103

[christiaan2]

Posted on August 06, 2015 at 13:11

I solved the interrupt problem by using TIM2 global interrupt. Problem now is by writing to CCR registers I change the phase shift and not the duty cycle.

Is this because in toggle mode the CCR registers are linked to the TIM_Pulse and this changes phase shift? If so could someone please guide me to how I would change the duty cycleThank you again#include ''stm32f10x.h''TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;TIM_OCInitTypeDef  TIM_OCInitStructure;TIM_BDTRInitTypeDef TIM_BDTRInitStructure;NVIC_InitTypeDef NVIC_InitStructure;int TimerPeriod = 0, n = 0;int Channel1Pulse = 0, Channel2Pulse = 0, Channel3Pulse = 0;uint16_t pulse_width = 0;void RCC_Configuration(void);void GPIO_Configuration(void);void PWM_SetDC(uint16_t dutycycle);void Delay(__IO uint32_t nCount);int main(void){ /* System Clocks Configuration */ SystemInit(); RCC_Configuration();  /* GPIO Configuration */  GPIO_Configuration();  /* TIM1 Configuration --------------------------------------------------- */ /* Compute the value to be set in ARR regiter to generate signal frequency at 10 Khz */ TimerPeriod = (SystemCoreClock / 22500);  /* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */  Channel1Pulse = (TimerPeriod / 6);  /* Compute CCR2 value to generate a duty cycle at 50%  for channel 2 and 2N with 60 degree phase shift*/  Channel2Pulse = (TimerPeriod / 6) + (TimerPeriod / 3);  /* Compute CCR3 value to generate a duty cycle at 50%  for channel 3 and 3N with 120 degree phase shift*/  Channel3Pulse = (TimerPeriod / 6) + ((TimerPeriod * 2) / 3); /* Enable the TIM2 gloabal Interrupt */ NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);  /* TIM2 clock enable */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); /* Time base configuration */ TIM_TimeBaseStructure.TIM_Period = 5000 - 1; TIM_TimeBaseStructure.TIM_Prescaler = 5 - 1; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); /* TIM IT enable */ TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE); /* TIM2 enable counter */ TIM_Cmd(TIM2, ENABLE); /* Time Base configuration */  TIM_TimeBaseStructure.TIM_Prescaler = 0;  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  TIM_TimeBaseStructure.TIM_Period = TimerPeriod - 1;  TIM_TimeBaseStructure.TIM_ClockDivision = 0;  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);  /* Channel 1, 2,3 and 4 Configuration in PWM mode */  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;  TIM_OCInitStructure.TIM_Pulse = Channel1Pulse; TIM_OC1Init(TIM1, &TIM_OCInitStructure);  TIM_OCInitStructure.TIM_Pulse = Channel2Pulse;  TIM_OC2Init(TIM1, &TIM_OCInitStructure);  TIM_OCInitStructure.TIM_Pulse = Channel3Pulse;  TIM_OC3Init(TIM1, &TIM_OCInitStructure); /* Dead time configuration (3.7 us) */  TIM_BDTRInitStructure.TIM_DeadTime = 183;  TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure); /* TIM1 IT Enable */// TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE); /* TIM1 counter enable */  TIM_Cmd(TIM1, ENABLE);  /* TIM1 Main Output Enable */  TIM_CtrlPWMOutputs(TIM1, ENABLE);  while (1)  { }}void RCC_Configuration(void){  /* TIM1, GPIOA, GPIOB and AFIO clocks enable */  RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); RCC_APB2PeriphResetCmd(RCC_APB2Periph_TIM1,DISABLE);}/* Configure the TIM1 Pins. */void GPIO_Configuration(void){ GPIO_InitTypeDef GPIO_InitStructure;   /* GPIOA Configuration: Channel 1, 2 and 3 as alternate function push-pull */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_Init(GPIOA, &GPIO_InitStructure);  /* GPIOB Configuration: Channel 1N, 2N and 3N as alternate function push-pull */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;  GPIO_Init(GPIOB, &GPIO_InitStructure);}void TIM2_IRQHandler(void){ if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) { TIM_ClearITPendingBit(TIM2, TIM_IT_Update); if (pulse_width <= 100)    {      PWM_SetDC(pulse_width++);    } else if (pulse_width > 100) { PWM_SetDC(pulse_width++); }    Delay(100); }}void PWM_SetDC(uint16_t dutycycle){    TIM1->CCR1 = dutycycle;    TIM1->CCR2 = dutycycle;    TIM1->CCR3 = dutycycle;}void Delay(__IO uint32_t nCount){  while(nCount--)  {  }}

[Tesla DeLorean]

Posted on August 06, 2015 at 14:37

Problem now is by writing to CCR registers I change the phase shift and not the duty cycle.

You set them all to the same thing, remember there is ONE counting element, TIMx->CNT, and there FOUR comparison registers watching the counter as it cycles through the period.if (TIMx->CNT == TIMx->CCR1) ToggleCH1Pin();You have to manage the phase (placement) you want for each of the edges, And then alternately the width of the MARK and SPACE you want. You have to manage each channel individually, and advance or retard it's setting to get the placement you want.

[christiaan2]

Posted on August 12, 2015 at 09:31

Thank you for replying clive

Could you please explain how I would control the placement of each channel's edge. I am new to ST hardware and don't quite understand everything yet but I am working on it.If I can control the edge placement with a register other than CCRx I could use PWM2 mode and control the duty cycle using the PULSE field which will set the values of the CCRx register if I understand correctly? All I need is a constant phase shift of 120 degrees between the three channels. The duty cycle will be updated by the interrupt (TIM1 interrupt or even TIM2 global interrupt)Thank you again