STM32F0 discovery I2C transfer using DMA

Question

I'm trying to get data from an I2C sensor (BNO055) using DMA, but I can't start DMA transmission. I've found plenty of examples for F1, F3 adn F4 STM microcontrollers, but nothing helpful for F0. What I do is:

I initialize sensor using poll method and it works fine.
I initialize DMA using this code:

`

void I2C1_DMA_Init(uint8_t *BNO055_DMA_buffer)
{
    RCC->AHBENR |= (RCC_AHBPeriph_DMA1);#
    DMA_InitTypeDef DMA_str;
    DMA_StructInit(&DMA_str);
    DMA_str.DMA_PeripheralBaseAddr = (uint32_t)I2C1->RXDR;
    DMA_str.DMA_MemoryBaseAddr = (uint32_t)BNO055_DMA_buffer;
    DMA_str.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_str.DMA_BufferSize = 32;
    DMA_str.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_str.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_str.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    DMA_str.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    DMA_str.DMA_Mode = DMA_Mode_Normal;
    DMA_str.DMA_Priority = DMA_Priority_VeryHigh;
    DMA_str.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel3, &DMA_str);
}

`

I set proper address of sensor memory to be read from using poll method.
Now I'd like to read 32 bytes using DMA. Do I have to send sensor address using I2C_TransferHandling() function? What other parameters should be sent then? What have I missed in DMA initialization that after executing:

I2C_DMACmd(I2C1, I2C_DMAReq_Rx, ENABLE); DMA_Cmd(DMA1_Channel3, ENABLE);

Nothing happens on the bus (I check it using logic analyzer).

Gürtaç Kadem Gürtaç Kadem · Accepted Answer · 2017-04-01T23:16:32

You can generate code using STMCubeMx. Also there are some DMA example codes for STM32F0 in STMCubeF0. I generated an I2C code for STM32F0 discovery board.

Your I2C init function can be as follow

    static void MX_I2C1_Init(void)
    {

      hi2c1.Instance = I2C1;
      hi2c1.Init.Timing = 0x2000090E;
      hi2c1.Init.OwnAddress1 = 0;
      hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
      hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
      hi2c1.Init.OwnAddress2 = 0;
      hi2c1.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
      hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
      hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
      if (HAL_I2C_Init(&hi2c1) != HAL_OK)
      {
        Error_Handler();
      }

        /**Configure Analogue filter 
        */
      if (HAL_I2CEx_ConfigAnalogFilter(&hi2c1, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
      {
        Error_Handler();
      }

    }

And DMA_Init function as follow

void HAL_I2C_MspInit(I2C_HandleTypeDef* hi2c)
{

  GPIO_InitTypeDef GPIO_InitStruct;
  if(hi2c->Instance==I2C1)
  {
  /* USER CODE BEGIN I2C1_MspInit 0 */

  /* USER CODE END I2C1_MspInit 0 */

    /**I2C1 GPIO Configuration    
    PB6     ------> I2C1_SCL
    PB7     ------> I2C1_SDA 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF1_I2C1;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* Peripheral clock enable */
    __HAL_RCC_I2C1_CLK_ENABLE();

    /* Peripheral DMA init*/

    hdma_i2c1_rx.Instance = DMA1_Channel3;
    hdma_i2c1_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_i2c1_rx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_i2c1_rx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_i2c1_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_i2c1_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_i2c1_rx.Init.Mode = DMA_NORMAL;
    hdma_i2c1_rx.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_i2c1_rx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(hi2c,hdmarx,hdma_i2c1_rx);

    hdma_i2c1_tx.Instance = DMA1_Channel2;
    hdma_i2c1_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_i2c1_tx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_i2c1_tx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_i2c1_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_i2c1_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_i2c1_tx.Init.Mode = DMA_NORMAL;
    hdma_i2c1_tx.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_i2c1_tx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(hi2c,hdmatx,hdma_i2c1_tx);

  /* USER CODE BEGIN I2C1_MspInit 1 */

  /* USER CODE END I2C1_MspInit 1 */
  }

}

After init functions you should call HAL_DMA_Start_IT.

STM32F0 discovery I2C transfer using DMA

1 Answers