SPI控制AD7792

Fansr's Blog

哪位用STM32F103控制过AD7792，NSS、SCK、MOSI上都有波形，MISO上就是没数！
/* SPI1 Master */
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
  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_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI1, &SPI_InitStructure);
  SPI_Cmd(SPI1, ENABLE);
 
    GPIO_SetBits(GPIOA, GPIO_Pin_4);
 
      Delay(500);//90uS
      GPIO_ResetBits(GPIOA, GPIO_Pin_4);
      // Wait for SPI1 Tx buffer empty
      while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
      // Send SPI1 ReadId for read AD7792 ID register
      SPI_I2S_SendData(SPI1,ReadID);
      while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
       SPI_I2S_SendData(SPI1, 0xA5);
      while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
      SPI1_Rx = SPI_I2S_ReceiveData(SPI1);
      GPIO_SetBits(GPIOA, GPIO_Pin_4);    
 
高人指点指点！

Fansr's Blog

// Wait for SPI1 Tx buffer empty
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
// Send SPI1 ReadId for read ID register
SPI_I2S_SendData(SPI1,ReadID);
Delay(500);
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
// Send SPI1 Dummy for SCK
SPI_I2S_SendData(SPI1, 0xF0);
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
SPIRx1 = SPI_I2S_ReceiveData(SPI1);
SPI时序过快，添加Delay(500)后可以稳定工作！
 

wangjianjia-274

 这位大哥能加个Q聊聊吗，我最近也在调这个AD7792  遇上了一些问题，希望与您交流
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