STM32H743 UART DMA接收不到数据

发布于 2025-01-18 12:41:47 浏览：64 订阅该版

主分支的bsp下stm32 拷贝的

配置如下:

```c
/* Device Drivers */

#define RT_USING_DEVICE_IPC
#define RT_UNAMED_PIPE_NUMBER 64
#define RT_USING_SERIAL
#define RT_USING_SERIAL_V2
#define RT_SERIAL_USING_DMA
#define RT_USING_PIN

/* On-chip Peripheral Drivers */

#define BSP_USING_GPIO
#define BSP_USING_ON_CHIP_FLASH
#define BSP_USING_UART
#define BSP_USING_UART3
#define BSP_UART3_RX_USING_DMA
#define BSP_UART3_RX_BUFSIZE 256
#define BSP_UART3_TX_BUFSIZE 128
#define BSP_USING_UART8
#define BSP_UART8_TX_BUFSIZE 128
#define BSP_UART8_RX_BUFSIZE 128

其中BSP_USING_UART8作为msh串口，对uart8除了msp.c的初始化，没有使用其他配置，msh使用正常.

对uart3 增加一下内容宏定义
/* DMA1 stream1 */
#if defined(BSP_UART3_RX_USING_DMA) && !defined(UART3_RX_DMA_INSTANCE)
#define UART3_DMA_RX_IRQHandler          DMA1_Stream1_IRQHandler
#define UART3_RX_DMA_RCC                 RCC_AHB1ENR_DMA1EN
#define UART3_RX_DMA_INSTANCE            DMA1_Stream1
#define UART3_RX_DMA_REQUEST             DMA_REQUEST_USART3_RX
#define UART3_RX_DMA_IRQ                 DMA1_Stream1_IRQn
#endif

```

main.c代码如下

```c
#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>

#define LED1_PIN    GET_PIN(C, 12)
/* 串口设备句柄 */
static rt_device_t serial;
int main(void)
{
		int rx_length;
		uint8_t buff[32];
    /* set LED2 pin mode to output */
    rt_pin_mode(LED1_PIN, PIN_MODE_OUTPUT);
	    /* 查找串口设备 */
    serial = rt_device_find("uart3");
    if (!serial)
    {
        rt_kprintf("find %s failed!\n", "uart3");
        return RT_ERROR;
    }
		/* 以 DMA 接收及轮询发送方式打开串口设备 */
    rt_device_open(serial, RT_DEVICE_FLAG_RX_NON_BLOCKING | RT_DEVICE_FLAG_TX_BLOCKING);
		
		rt_device_write(serial, 0, "hello", (strlen("hello")));
    while (1)
    {
			rx_length = rt_device_read(serial, 0, buff, 32);
			if(rx_length>0)
			{
				rt_kprintf("%*s\n",rx_length,buff);
			}
        rt_pin_write(LED1_PIN, PIN_HIGH);
        rt_thread_mdelay(1000);
        rt_pin_write(LED1_PIN, PIN_LOW);
        rt_thread_mdelay(1000);
    }
}

```
使用串口助手，PC端能收到“hello”，但是PC端下发的数据，没有收到。

如果配置上不使用DMA，串口收发没问题。