UARTDMA How to work

First, initialize

1. Initialize the serial port, clock

Mx_usart1_uart_init ();

Serial clock initialized to internal clock

Periphclkinit.usart1clockselection = RCC_USART1CLKSOURCE_HSI;

Periphclkinit.usart2clockselection = RCC_USART2CLKSOURCE_HSI;

2. Initializing DMA, Port multiplexing

Hal_uart_mspinit ()

Open Idle Frame Interrupt

__hal_uart_enable_it (Uarthandle, Uart_it_idle);

Second, start receiving transmission

1. Start Data reception

/*Start DMA Receive transfer*/voidMx_uart_debugrxstart (uart_e Uart) {if(uart>= Uart_max) {return ;} if(!g_stmyuart[uart].bdebugrxstop) {return ;}  for(Uint8 i=0; i<uart_debug_buff_lever;i++)    {        if(!G_stmyuart[uart].bdebugrxavail[i]) {G_stmyuart[uart].bdebugrxstop=false; HAL_UART_RECEIVE_DMA (G_stmyuart[uart].huart, g_stmyuart[uart].cdebugbuffrx[i], uart_rx_buff_size -1); G_stmyuart[uart].ccurdebugrxbuff=i; G_stmyuart[uart].udebugrxcount[i]=0;  Break; }    }}

2. If the data is received, the DMA interrupt is triggered, when the DMA interrupt is triggered, the call transfer completes the interrupt, and if the free frame is received, the transfer completion interrupt is also called.

uint32_t temp;     = huart->instance->ISR;     = huart->instance->RDR;     if (HAL_OK! =hal_uart_dmastoprx (huart))    {        error_handler ();    }    G_stmyuart[uart].bdebugrxstop=true;     if (NULL! = huart->Hdmarx)    {        temp  = huart->hdmarx->instance->cndtr;        Mx_uart_debuggetdata (uart,temp);        Mx_uart_debugrxstart (Uart);    }     Else {Error_Handler ();}

Stop DMA transfer, set receive Stop flag, read data, restart data reception

Third, send DMA

1. Start the transfer

if (HAL_UART_TRANSMIT_DMA (G_stmyuart[uart_debug].huart                      , g_stmyuart[uart_debug].cdebugbufftx[i]                      = = Hal_ok)                    {                        G_stmyuart[uart_debug].ccurdebugtxbuff=i;                        G_stmyuart[uart_debug].udebugtxcount[i]=0;                    }

When the 2.DMA transfer is complete, open the serial port send complete interrupt,

void Hal_uart_txcpltcallback (Uart_handletypedef *huart) {    uart_e UART;      for (uart=uart_debug;uart<uart_max;uart++)    {        if(G_stmyuart[uart].huart = = Huart){break;    }    } if (Uart_max = = UART) {return  ;}    Hal_uart_dmastoptx (Huart);     if (G_stmyuart[uart].ccurdebugtxbuff <uart_debug_buff_lever)    {        G_stmyuart[uart].bdebugtxen[g_stmyuart[uart].ccurdebugtxbuff]=false;    }}

UARTDMA How to work