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Trying to make a PWM (2 channel + 2 Channel Complimentory) by using DMA

thannara123
Associate III

I am trying to make a pwm signal ,with Lookup table for duty cyle .

Here using TIM1 of stm32nucleoF070.

I am here using DMA ,reffered a lot of from google and just worte as follows 

 

No variying singal is getting 

SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_TIM1_Init();
  /* USER CODE BEGIN 2 */

 HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_1, (uint32_t *)sin_table, 32);
  HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_2, (uint32_t *)sin_table, 32);
  HAL_TIM_Base_Start_IT(&htim1);
  HAL_TIM_PWM_Start_IT(&htim1, TIM_CHANNEL_1);
  HAL_TIMEx_PWMN_Start_IT(&htim1, TIM_CHANNEL_1);
  HAL_TIM_PWM_Start_IT(&htim1, TIM_CHANNEL_2);
  HAL_TIMEx_PWMN_Start_IT(&htim1, TIM_CHANNEL_2);


  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */

	 HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_5);
			  	  	  	  HAL_Delay(80);
//

  }

is it correct way , 

any help is appriciated 

 

1 REPLY 1
Pierre_Paris
ST Employee

Hello @thannara123,

Thank you for your question !

Here are some remark:

  • Why are you casting "sin_table" ? My advise is to declare this array as an uint32_t and to delete the cast.
  • When you call the HAL_TIM_PWM_Start_DMA(), you start the PWM signal generation in DMA mode. Also, it's better to call it that way :

 

  if (HAL_TIM_PWM_Start_DMA(&TimHandle, TIM_CHANNEL_3, aCCValue_Buffer, 3) != HAL_OK)
  {
    /* Starting Error */
    Error_Handler();
  }​

 

  • You cannot call line 15-19 and start in interrupt mode, you started in DMA mode just before...
  • Have you consider the CubeFW example on TIM under the root "STM32Cube_FW_F0_V1.11.0\Projects\STM32F070RB-Nucleo\Examples\TIM" ? You can download the zip here.

Best Regards,

Pierre

 

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