Posted by Sce_1 on 2017-06-20 10:46

Hi
My example for UART DMA

1. define MAX_NUM_CHAR_FOR_MESSAGE 64

1. ifdef UART_1

extern UART_HandleTypeDef huart1;

1. define BUFFER_UART1_TX_MAX MAX_NUM_CHAR_FOR_MESSAGE
2. define CIRCULAR_BUFFER_UART1_RX_MAX 256
3. ifdef UART_1_DMA

extern DMA_HandleTypeDef hdma_usart1_rx;

1. endif
2. endif

HAL_StatusTypeDef InitUart_IT_DMA(BYTE ucCom)
{
HAL_StatusTypeDef ret = HAL_ERROR;

switch (ucCom) {

#ifdef UART_1
case UART_1:
bTx1Running = FALSE;
#ifdef UART_1_DMA
ret = HAL_UART_Receive_DMA(&huart1, (uint8_t *)ucRx1, CIRCULAR_BUFFER_UART1_RX_MAX);
uiIdxWrRx1 = CIRCULAR_BUFFER_UART1_RX_MAX - hdma_usart1_rx.Instance->NDTR;
#else
uiIdxWrRx1 = 0;
ret = HAL_UART_Receive_IT(&huart1, (uint8_t *) &ucRx1uiIdxWrRx1, 1);
#endif
uiIdxRdRx1 = uiIdxWrRx1;
break;
#endif
default:
ret = HAL_ERROR;
break;
}
return ret;
}

Posted by Adrian A on 2017-06-22 02:15

You can set up a DMA circular buffer with the MXCube really easily, and just set the receive length to a really large number when you command the DMA receive. For example:

HAL_UART_Receive_DMA(&huart2, gps_circ, 0xFFFFFFFFu); //number of bytes is 2^32, good for about 83 hours continuously at 110kbps