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Change Polarity of PWM with DMA in circular mode

thannara123
Senior

Hello Experts ,

I am generating a two-Channel PWM with complementary channels also 

 

 

HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_1, (uint32_t *)sin_table, 20);//low
HAL_TIMEx_PWMN_Start_IT(&htim1, TIM_CHANNEL_1);
HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_2, (uint32_t *)sin_table, 20); //high
HAL_TIMEx_PWMN_Start_IT(&htim1, TIM_CHANNEL_2);

 

 

I am using DMA in circular mode .

I require when the total complete transfer occur the Polarity of the above channel ie Channel 1 and channel should or change . 

 

@BarryWhit 

@MM..1 

@Sarra.S 

 

 

 

void PWM_PulseFinishedCallback(TIM_HandleTypeDef *htim)
{    if (htim->hdma[TIM_DMA_ID_CC1] != NULL && htim->hdma[TIM_DMA_ID_CC1] == &hdma_tim1_ch1)
       {
          HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_5);

          if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1)
              {
 HAL_TIM_PWM_Stop_DMA(&htim1, TIM_CHANNEL_1);
                 HAL_TIMEx_PWMN_Stop(&htim1, TIM_CHANNEL_1);
                  // Stop PWM on CH2 and CH2N before toggling polarity
                 HAL_TIM_PWM_Stop_DMA(&htim1, TIM_CHANNEL_2);
                HAL_TIMEx_PWMN_Stop(&htim1, TIM_CHANNEL_2);
                 // Toggle the polarity bits for CH1 and CH1N
                htim1.Instance->CCER ^= (TIM_CCER_CC1P | TIM_CCER_CC1NP);
                // Toggle the polarity bits for CH2 and CH2N
               htim1.Instance->CCER ^= (TIM_CCER_CC2P | TIM_CCER_CC2NP);
HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_1, (uint32_t *)sin_table, 200);
	                HAL_TIMEx_PWMN_Start_IT(&htim1, TIM_CHANNEL_1);
	                HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_2, (uint32_t *)sin_table, 200);
	                HAL_TIMEx_PWMN_Start_IT(&htim1, TIM_CHANNEL_2);

 

 

I tried the following way , After trigger the callback it stops the PWM and not start again ?

How can obtain it ?

 

2 REPLIES 2
MM..1
Chief III

Forget to use HAL for continuos operations. Maybe with right usage half and full complete callbacks and rewrite arrays for DMA. For continuos PWM never break TIM setup only change CCR values...