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USART->DMA using STM32F3 Discovery

heinz
Associate II
Posted on September 20, 2016 at 21:49

Hi,

I've been struggling to get interrupt for DMA working. I got it working for USART interrupt.

I'm configuring for USART1 and DMA1_Channel5.

My problem is that I don't get an interrupt for the DMA.

So is there something I miss during the configuration?

Regards

main.c

void USART1_IRQHandler(void)

{

}

void DMA1_Channel5_IRQHandler(void)

{

    // do something

}

main(void)

{

    NVIC_SetPriorityGrouping(PRIORITY_GROUP);

    NVIC_SetPriority(DMA1_Channel5_IRQn, NVIC_EncodePriority(PRIORITY_GROUP, 1, 1));   // DMA

    NVIC_SetPriority(USART1_IRQn, NVIC_EncodePriority(PRIORITY_GROUP, 2, 0));           // USART1

    NVIC_SetPriority(SysTick_IRQn, NVIC_EncodePriority(PRIORITY_GROUP, 2, 2));           // SysTick

    bsp_init();

    while (1)

    {

        // just loop 4 ever 🙂

    }

}

bsp.c

void GPIO_Usart_1_Configuaration(void)

{

    GPIO_InitTypeDef GPIO_InitStructure;

    // enable USART clocks

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

    // setup port A

    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;

    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

    GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_9 |  // USART1_TX

                                    GPIO_Pin_10;  // USART1_RX

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_7);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_7);

    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // setup USART1

    USART_InitTypeDef USART_InitStructure;

    USART_ClockInitTypeDef USART_ClockInitStructure;

    // setu up USART1_ClockInitStruct member with its default value

    USART_ClockStructInit(&USART_ClockInitStructure);

    USART_ClockInit(USART1, &USART_ClockInitStructure);

    

    USART_InitStructure.USART_BaudRate            = BAUDRATE_9600;

    USART_InitStructure.USART_WordLength          = USART_WordLength_8b;

    USART_InitStructure.USART_StopBits            = USART_StopBits_1;

    USART_InitStructure.USART_Parity              = USART_Parity_No;

    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

    USART_InitStructure.USART_Mode                = USART_Mode_Rx | USART_Mode_Tx;

    USART_Init(USART1, &USART_InitStructure);

    // enable DMA interface for RX

    USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);  // USART_CR3, 0x4001 3808

    // enable USART1 port

    USART_Cmd(USART1, ENABLE);

    // enable CM, RXNE interrupt

    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);

    // enable USART1 global interrupt

    NVIC_EnableIRQ(USART1_IRQn);

}

void GPIO_Dma_1_Configuaration(void)

{

    DMA_InitTypeDef DMA_InitStructure;

    // enable DMA clocks

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

    /* DMA2 channel5 configuration */

    DMA_DeInit(DMA1_Channel5);

    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->RDR;          // DMA_CPAR, 0x4002 0060

    DMA_InitStructure.DMA_MemoryBaseAddr     = 0x00000000;                      // DMA_CMAR, 0x4002 0064

    DMA_InitStructure.DMA_DIR                = DMA_DIR_PeripheralSRC;

    DMA_InitStructure.DMA_BufferSize         = RX_BUFFER_SIZE;                  // DMA_CNDTR, 0x4002 005C

    DMA_InitStructure.DMA_PeripheralInc      = DMA_PeripheralInc_Disable;

    DMA_InitStructure.DMA_MemoryInc          = DMA_MemoryInc_Enable;

    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

    DMA_InitStructure.DMA_MemoryDataSize     = DMA_MemoryDataSize_Byte;

    DMA_InitStructure.DMA_Mode               = DMA_Mode_Circular;

    DMA_InitStructure.DMA_Priority           = DMA_Priority_High;               // DMA_CCR, 0x4002 0058

    DMA_InitStructure.DMA_M2M                = DMA_M2M_Disable;

    DMA_Init(DMA1_Channel5, &DMA_InitStructure);

    // enable DMA interrupt

    NVIC_EnableIRQ(DMA1_Channel5_IRQn);

    // enable transfer complete interrupt

    DMA_ITConfig(DMA1_Channel5, DMA_IT_TC, ENABLE);

    // enable DMA1 channel5

    DMA_Cmd(DMA1_Channel5, ENABLE);

}

// initialize clocks and GPIO ports

void bsp_init(void)

{

    GPIO_Usart_1_Configuaration();

    GPIO_Dma_1_Configuaration();

}

#stm32
2 REPLIES 2
Posted on September 21, 2016 at 00:35

Zero isn't going to be a viable buffer address here.

You should provide enough code for this to compile and be testable, a bunch of definitions missing.

Tips, buy me a coffee, or three.. PayPal Venmo Up vote any posts that you find helpful, it shows what's working..
heinz
Associate II
Posted on September 21, 2016 at 09:00

About the code, yes I just cut out what I thought was the important stuff.

Nevertheless I changed my buffer address to:

DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)rx_buffer;

I have a declaration further up in the code:

char rx_buffer[2];

And now I can see that I get a DMA interrupt.

At least one step ahead.

Thank You Clive1.