STM32 SPI 主从通信,主机接收到从机数据第一位数据不对

只看该作者 · 2022-3-1 15:03

主机发送0xa2,从机接收主机发送的数据,判断接收到的数据是不是0xa2,如果从机接收到的数据是0xa2,从机发送:0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c给主机.但是主机接到的是:0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b.

```
uint16_t SPI2_ReadWriteByte(uint16_t TxData)
{
      while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) == RESET);       // 等待发送区空
      SPI_I2S_SendData(SPI2, TxData);                                                                // 通过外设SPIx发送一个byte数据
      while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET);// 等待接收完一个byte
      return SPI_I2S_ReceiveData(SPI2);                                                                // 返回通过SPIx最近接收的数据
}
uint8_t SPI_TxBuffer[12] = {0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c};
void SPI2_IRQHandler(void)
{
      if(LL_SPI_IsActiveFlag_RXNE(SPI2)==SET){
            SPI_IT_Rec=SPI2->DR;
            if(SPI_IT_Rec == 0xa2){
                     for(uint8_t i=0;i<12;++i){

                              SPI_RxBuffer= ReadWriteData(SPI_TxBuffer);
                     }
                     SPI_Flag = 1;
            }
      }
}
```