AnsweredAssumed Answered

SPI Problem(NO SCK Signal when receiving)

Question asked by kim.andy on May 15, 2013
Latest reply on May 15, 2013 by kim.andy
Hi, everyone.

I am trying to control a slave device by SPI Communication.
But I have a problem with SPI, SCK is not output when receiving a data. Tx is OK.
Why does this problem happen?
I hope you help me to slove this problem.

The belowing is my code

void bsp_init_rcc(void)

 /* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/  
 /* RCC system reset(for debug purpose) */
 RCC_DeInit();
 
 /* Enable HSE */
 RCC_HSEConfig(RCC_HSE_ON);
 
 /* Wait till HSE is ready */
 HSEStartUpStatus = RCC_WaitForHSEStartUp();
 
 ..................................................

 
 /* Enable GPIOA, GPIOB, GPIOC, GPIOD, GPIOE and AFIO clocks */
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE | RCC_APB2Periph_AFIO, ENABLE);
       
 /* Enable peripheral clocks --------------------------------------------------*/
 /* SPI1 clock enable */
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
 
 /* SPI2 Periph clock enable */
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
}

void bsp_init_gpio(void)
{
 GPIO_InitTypeDef GPIO_InitStructure;
 
  /* Configure SPI1 pins: SCK, MISO and MOSI ---------------------------------*/
 /* Confugure NSS, SCK and MOSI pins as Alternate Function Push Pull */
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
 GPIO_Init(GPIOA, &GPIO_InitStructure);
 
 /* Confugure MISO pin as Input Floating  */
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
 GPIO_Init(GPIOA, &GPIO_InitStructure);

 /* Confugure NSS pin as Output  */
 GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_4 ;
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
 GPIO_Init(GPIOA, &GPIO_InitStructure); 
}

void spi_init(void)
{
  /* SPI1 configuration ------------------------------------------------------*/
  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_Low;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI1, &SPI_InitStructure);
 
  /* Enable SPI1 CRC calculation */
  SPI_CalculateCRC(SPI1, ENABLE);

 SPI_SSOutputCmd(SPI1, ENABLE);

 /* Enable SPI1 */
  SPI_Cmd(SPI1, ENABLE);
 
 SPI_NSS_High();
}

void SPI_tx_data(uint8_t data)
{
  /* Wait for SPI1 Tx buffer empty */
  while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);

 SPI_NSS_Low();
  SPI_I2S_SendData(SPI1, data);
 while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET) ;
 SPI_NSS_High();
}

uint8_t SPI_rx_data(void)
{
 uint8_t data;

 /* Wait for SPI1 data reception */
 while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
 
 SPI_NSS_Low();
  data = SPI_I2S_ReceiveData(SPI1);
 SPI_NSS_High();
 
 return data;
}

Please help me


Outcomes