Usage DMA and DAC in STM32CubeMX

ST released new HAL library, together with STM32CubeMX codegeneration tool. They are good things, but still have too few documentation and articles in the Internet.

I've tried to use DAC in couple with DMA in my board STM32F4Discovery. So, I'll describe the whole process of developing sine wave generator using STM32CubeMX utility and IAR.

First of all, we'll start new project in cube. We have "board Selector" tab, where we select our STM32F4discovery board.

We set all not necessary pins at reset state - we do not neet it.

We set all not necessary pins at reset state - we do not need it. And set PA4 as DAC_OUT1. Now picture is:

What else we need? We need timer, which will send requests to DMA controller. I've chosen TIM6. To enable it, in "Configuration" tree, select "Peripherals->TIM6->Activated" branch and check it.

Ok, now move to configuration tab. We need to tune TIM6, DAC and DMA.

For TIM6 

We need to set:

• prescaler and trigger event(just press TIM6 button):

For DAC

We need to set:

• on parameter settings: Trigger = Timer 6 Trigger Out event
• on NVIC Settings set enabled global interrupt
• on DMA settings:
  
  press "add", then set settings as on picture.Do not forget set "Mode" as "Circular" and set "data width" as "half-word"!
      "Circular" means that after the counter reaches the end of array, reading starts on the end. "Data width" - means "on pieces,    of which length source array sliced will be". So, our sine wave will be stored in uint16_t array, so we need half-word mode(16 bit).    32 bit - is a word.
  Now, save project and press on gear button in toolbar - this generates code. Open project in IAR.

So, this is almost all. And now we'll see another wonderful side of CubeMX - the amount of additional code is just 4 lines:
first, we need to make additional global variable at main.c file(look to /* USER CODE BEGIN PV */ section, created by CubeMX code)
here we'll place

 /* USER CODE BEGIN PV */  
 const uint16_t sine_wave_array[32] = {2047, 1648, 1264, 910, 600,  345,   
                    156, 39,  0,  39,  156,  345,  
                    600, 910, 1264, 1648, 2048, 2447,  
                    2831, 3185, 3495, 3750, 3939, 4056,  
                    4095, 4056, 3939, 3750, 3495, 3185,  
                    2831, 2447};  
 /* USER CODE END PV */  

and in main() function we'll add

  /* USER CODE BEGIN 2 */  
  HAL_TIM_Base_Start(&htim6);  
  HAL_DAC_Start(&hdac,DAC_CHANNEL_1);  
  HAL_DAC_Start_DMA(&hdac, DAC_CHANNEL_1, (uint32_t*)sine_wave_array, 32, DAC_ALIGN_12B_R);  
  /* USER CODE END 2 */  

•  first line - starts the timer
•  second - starts DAC
•  third - starts DMA and assign our array to DMA.

finally, our main() function looks like:

 int main(void)  
 {  
  /* USER CODE BEGIN 1 */  
  /* USER CODE END 1 */  
  /* MCU Configuration----------------------------------------------------------*/  
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */  
  HAL_Init();  
  /* Configure the system clock */  
  SystemClock_Config();  
  /* Initialize all configured peripherals */  
  MX_GPIO_Init();  
  MX_DMA_Init();  
  MX_DAC_Init();  
  MX_TIM6_Init();  
  /* USER CODE BEGIN 2 */  
  HAL_TIM_Base_Start(&htim6);  
  HAL_DAC_Start(&hdac,DAC_CHANNEL_1);  
  HAL_DAC_Start_DMA(&hdac, DAC_CHANNEL_1, (uint32_t*)sine_wave_array, 32, DAC_ALIGN_12B_R);  
  /* USER CODE END 2 */  
  /* USER CODE BEGIN 3 */  
  /* Infinite loop */  
  while (1)  
  {  
  }  
  /* USER CODE END 3 */  
 }