星火一号串口发送问题

发布于 2023-10-09 17:14:19 浏览：577 订阅该版

使用星火一号开发板测试485的时候，发现一个问题，这个板子硬件电路是有485控制引脚的，配置完串口参数，中断接收数据，接收的数据是正常的，然后引脚改为发送模式，发送的数据是不对的，是什么原因导致的呢

```c
static rt_err_t uart6_callback( rt_device_t dev, rt_size_t size )
{
    struct rx_msg msg;
    msg.dev  = dev;
    msg.size = size;
    /* send msg to mq */
    rt_mq_send( &uart6_mq, &msg, sizeof(struct rx_msg) );
    return RT_EOK;
}

/**< rs485  配置部分代码 */
/* find uart device */
uart6_serial = rt_device_find( UART6_NAME );
/* uart configuration */
rt_device_control( uart6_serial, RT_DEVICE_CTRL_CONFIG , &uart6_config );
/* set callback function */
rt_device_set_rx_indicate( uart6_serial, uart6_callback );
/* open uart device */
rt_device_open( uart6_serial,  RT_DEVICE_FLAG_INT_RX );

/**
 * @brief   send msg by rs485
 * @param   msg pointer
 * @param   msg size
 * @return  none
 */
void RS485_msg_send( rt_uint8_t *buffer, rt_size_t  size )
{
    /* send mode */
    rt_pin_mode( RS485_RE, PIN_MODE_INPUT );
    rt_device_write( uart6_serial, 0, buffer, size );
    /* recv mode */
    rt_pin_mode( RS485_RE, PIN_MODE_OUTPUT );
}

/* 要发送的数据 */
/**
 * @brief   rs485 recv msg
 * @param   void
 * @retval  none
 */
void rs485_recv_msg(void)
{
    rt_uint8_t arr[10] = {0};
    rt_uint16_t crc;

arr[0] = 0x01;
    arr[1] = 0x03;
    arr[2] = 0x02;
    /* data*/
    arr[3] = 0x00;
    arr[4] = 0x06;
    /* crc */
    crc = modbus_crc_calc( arr, 5 );
    arr[5] = GET_BYTEL( crc );
    arr[6] = GET_BYTEH( crc );

RS485_msg_send( arr, 7 );
}
```

![uart.png](https://oss-club.rt-thread.org/uploads/20231009/980d2d5f84c28605dcaba9b9da9ddcfd.png)