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STM32F303 Discovery: SPI basics
von Harald (Guest)

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Hi,

I try my first programming on an STM32 Discovery Board (STM32F303). I 
was using avrs before for years :-)

First step should be to get the SPI to work. My IDE is Eclipse with gnu 
arm eclipse-plugin.
All I want to see for now is the working SPI on an oscilloscope.
But the following code shows nothing at CLK or MOSI:

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int main(int argc, char* argv[])

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{

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  BlinkLed blinkLed; 

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  GPIO_InitTypeDef GPIO_InitStructure;

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  SPI_InitTypeDef SPI_InitStructure;

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  blinkLed.powerUp();

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  RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);

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  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);

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  // PB13 = SCK; PB15 =  MOSI

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  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_13 | GPIO_Pin_15;

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  GPIO_InitStructure.GPIO_Mode   = GPIO_Mode_AF;

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  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

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  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

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  GPIO_Init(GPIOB, &GPIO_InitStructure);

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  GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_6);

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  GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_6);

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  // Chip select pin

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  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_8;

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  GPIO_InitStructure.GPIO_Mode   = GPIO_Mode_OUT;

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  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

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  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

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  GPIO_Init(GPIOB, &GPIO_InitStructure);

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  GPIO_SetBits(GPIOB, GPIO_Pin_8);

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  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;

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  SPI_InitStructure.SPI_CPHA       = SPI_CPHA_2Edge;

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  SPI_InitStructure.SPI_CPOL       = SPI_CPOL_High;

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  SPI_InitStructure.SPI_CRCPolynomial     = 1;

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  SPI_InitStructure.SPI_DataSize     = SPI_DataSize_8b;

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  SPI_InitStructure.SPI_Direction     = SPI_Direction_1Line_Tx;

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  SPI_InitStructure.SPI_FirstBit     = SPI_FirstBit_MSB;

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  SPI_InitStructure.SPI_Mode       = SPI_Mode_Master;

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  SPI_InitStructure.SPI_NSS       = SPI_NSS_Soft;

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  SPI_Init(SPI2, &SPI_InitStructure);

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  SPI_Cmd(SPI2, ENABLE);

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  uint8_t i = 0;

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  while (1)

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    {

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      i++;

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      blinkLed.turnOff();

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      SPI_SendData8(SPI2, i);

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      while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_BSY) == SET)

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    {};

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      blinkLed.turnOn();

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    }

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}


Is there any bus or clock I didn't switch on?
Trouble with the TX-FiFos? Must I use the TX-Interrupt?
I inspected the code with the debugger - it cycles correctly through the 
while-loop...

Any help would be appreciated. Thank you.

  


  




  

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    Re: STM32F303 Discovery: SPI basics
  


  

    

      von
      
        Harald G.
        (andobrawan)
        
      
      


      
    


    

      
    

    

    

  
  


  

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Wrong alternate port-function!!!!
Changed it to GPIO_AF_5 and it works.

GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_5);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_5);

Further on I had to add a line in the GPIO_InitStructure:
GPIO_InitStructure.GPIO_PuPd   = GPIO_PuPd_NOPULL;

  


  




  

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