请教，spi从机发送不能接收的问题

鸡蛋饭 · 发表于 2016-10-23 16:44:20

主机发送给从机，数据正常，
但是从机不能给主机发送数据，代码如下，求高手解答

void SPI1_Config(void)
{
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);//使能spi1
  SPI_InitTypeDef  SPI_InitStructure;
  SPI_Cmd(SPI1, DISABLE);
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;//SPI_Mode_Slave
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;    //
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;//SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI1, &SPI_InitStructure);

  SPI_Cmd(SPI1, ENABLE);

}

void SPI2_Config(void)
{
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);//使能spi2
  SPI_InitTypeDef  SPI_InitStructure;
  SPI_Cmd(SPI2, DISABLE);
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;//SPI_Mode_Master
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;

  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_128;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;//SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI2, &SPI_InitStructure);

  SPI_Cmd(SPI2, ENABLE);
}

void GPIO_Config()
{
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//使能GPIOA时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);//使能GPIOB时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
  //spi1
  GPIO_InitTypeDef GPIO_InitStructure;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5|GPIO_Pin_7;//sck mosi
  GPIO_Init(GPIOA,&GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;//miso
  GPIO_Init(GPIOA,&GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;//cs
  GPIO_Init(GPIOA,&GPIO_InitStructure);

  //spi2
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //推挽复用
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_15;//sck mosi
  GPIO_Init(GPIOB,&GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;//miso
  GPIO_Init(GPIOB,&GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;//cs
  GPIO_Init(GPIOB,&GPIO_InitStructure);
}

void SPI_Send(SPI_TypeDef* SPIx,u16 data)
{
  while((SPIx->SR &SPI_I2S_FLAG_TXE)==RESET);
  SPIx->DR = data;
}
u16 SPI_Receive(SPI_TypeDef* SPIx)
{
  while((SPIx->SR &SPI_I2S_FLAG_RXNE)==RESET);
  return SPIx->DR;
}

int main(void)
{
  SystemInit();

  SPI1_Config();
  SPI2_Config();
  GPIO_Config();

  SPI_Send(SPI1,0x12);
  temp=SPI_Receive(SPI2);

  SPI_Send(SPI1,0x21);
  temp=SPI_Receive(SPI2);
//spi1发送，spi2正常接收

//spi2发送， spi1接收错误
  SPI_Send(SPI2,0x22);
  temp=SPI_Receive(SPI1);//第一次temp值为0，

  SPI_Send(SPI2,0x22);//第二次不能发送
  temp=SPI_Receive(SPI1);

  while (1)
  {

  }
}