SPI protocol STM32F303

Posted on April 04, 2015 at 08:49

Hi,

I am a newbie in the field of micro-controllers and I'm having trouble programming the GPIOA parts as SPI1. Could someone please tell me where I could be going wrong? I would greatly appreciate if someone points me towards SPI implementation examples. The routines I've written so far are given below. I am trying to send just a byte of data and I am using a logic analyzer to check if there's a clock on SCK pin but I don't see anything happen. I also tried toggling an LED by sending data continuously but even this fails. 

void spi_initialization(void)

{

SPI_I2S_DeInit(SPI1);

SPI_InitStructure.SPI_Direction= SPI_Direction_1Line_Tx;

SPI_InitStructure.SPI_Mode= SPI_Mode_Master;

SPI_InitStructure.SPI_DataSize= SPI_DataSize_8b;

SPI_InitStructure.SPI_CPOL=SPI_CPHA_2Edge;

SPI_InitStructure.SPI_CPHA= SPI_CPOL_High;

SPI_InitStructure.SPI_NSS=SPI_NSS_Soft ;

SPI_InitStructure.SPI_BaudRatePrescaler=SPI_BaudRatePrescaler_2;

SPI_InitStructure.SPI_FirstBit=SPI_FirstBit_MSB;

SPI_InitStructure.SPI_CRCPolynomial=7;

SPI_Init(SPI1,&SPI_InitStructure);

SPI_RxFIFOThresholdConfig(SPI1, SPI_RxFIFOThreshold_QF);

/* Enable SPI1 CRC calculation */   

  SPI_CalculateCRC(SPI1, ENABLE);  

//SPI_BiDirectionalLineConfig(SPI1, SPI_Direction_Tx);

 

SPI_Cmd(SPI1, ENABLE);

}

void send_byte(uint8_t val)

{

    GPIO_ResetBits(GPIOA, GPIO_Pin_4); // CS low

    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET); //wait buffer empty

    SPI_SendData8(SPI1, val);

    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET); //wait finish sending

    GPIO_SetBits(GPIOA, GPIO_Pin_4); // CS high

}

void RCC_config()

{

//System clock set as HSI

RCC_SYSCLKConfig(RCC_SYSCLKSource_HSI);

// clock freq is 4MHz

RCC_HCLKConfig(RCC_SYSCLK_Div2); 

 // CLock freq divided by 2 to get 2MHz again on APB2 peripherals for SPI1

//RCC_PCLK2Config(RCC_HCLK_Div1);

 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOE, ENABLE);

 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);

}

void GPIO_config()

{

// Setting the pins for alternate mode SPI configura MOSI, SS, SCK

//GPIO_PinAFConfig(GPIOA, GPIO_PinSource4|GPIO_PinSource5|GPIO_PinSource7, GPIO_AF_5);

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

// Set GPIO pin for reset of LCD

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_15;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_Init(GPIOE, &GPIO_InitStructure);

// Set GPIO pin as NO PULL for RS functionality

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_15;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_Init(GPIOB, &GPIO_InitStructure);

}

int main(void)

{

// Initialize clocks

RCC_config();

GPIO_config();

spi_initialization();

send_byte(0xFF);

}

 

#spi-protocol-stm32f303