STM32F4 verliert letztes Bit bei SPI-Kommunikation (MISO)

tSpiError spiInit()

{

  GPIO_InitTypeDef   GPIO_InitStructure;

  NVIC_InitTypeDef   NVIC_InitStructure;

  EXTI_InitTypeDef    EXTI_InitStructure;

  SPI_InitTypeDef    SPI_InitStructure;

  tSpiError       Error = SpiNoError;

  // SPI1_NSS - PA15, SPI1_CLK - PB3, SPI1_MISO - PB4, SPI1_MOSI - PB5

  // EXT_INT_1 - PA1 to detect CS both edges

  // Peripheral Clock Enable -------------------------------------------------

  // Enable the SPI1 clock

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);

  // Enable GPIO clocks

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

  // DEBUG-PIN

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;

  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // SPI GPIO Configuration --------------------------------------------------

  // Connect SPI pins to AF5

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource15, GPIO_AF_SPI1); // CS

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource3, GPIO_AF_SPI1); // SCK

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource4, GPIO_AF_SPI1); // MISO

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource5, GPIO_AF_SPI1);  // MOSI

  // MISO, MOSI

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;

  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // SCK

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;

  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // CS - Software controlled

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_SetBits(GPIOA, GPIO_Pin_15);

  // SPI configuration -------------------------------------------------------

  SPI_I2S_DeInit(SPI1);

  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;

  //SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;

  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;

  //SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b;

  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_NSS = SPI_NSS_Soft;

  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_32;

  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;

  SPI_InitStructure.SPI_CRCPolynomial = 0;

  SPI_Init(SPI1, &SPI_InitStructure);

  // Configure the SPI interrupt priority

  NVIC_InitStructure.NVIC_IRQChannel = SPI1_IRQn;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = SPI_INTERRUPT_PRIO;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;//(uint8_t) SpiSimInst_p;

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

  NVIC_Init(&NVIC_InitStructure);

  // Enable the Rx buffer not empty interrupt

  SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_TXE, ENABLE);

  SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_RXNE, ENABLE);

//  SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_ERR, ENABLE);

  // Enable the SPI peripheral

  // Enable in Slave-Mode should be done with CS-Signal -> additional EXTI-Input

  //SPI_Cmd(SPI1, ENABLE);

  // SPI_SSOutputCmd(SPI1, ENABLE);

Exit:

  return Error;

}