Using SPI with STM32L4R9 Discovery Board

[magene]

Unfortunately there isn't an example provided for SPI on the STM32L4R9 Disco board. I can tell from the User Manual that I need to set the quad SPDT switch on the board to the SPI configuration. If I understand table 20 in the User Manual, I need to set GPIO6 and GPIO7 of the MFX to 0. There are dozens of functions in the STM32l4R9i-discoveryxx.c and mfxstm32l152.c files so I'm confused about how to initialize and use the MFX. Can someone point me at some example code that explains how to set up and use the MFX on the STM32L4R9 discovery board to set some GPIO lines?

Thanks

[Tesla DeLorean · Accepted solution]

Look at the BSP_IO implementation

void BSP_LED_Init(Led_TypeDef Led)
{
  GPIO_InitTypeDef  GPIO_InitStructure;
 
  if (Led == LED2)
  {
    /* Enable the GPIO_LED clock */
    LED2_GPIO_CLK_ENABLE();
 
    /* Configure the GPIO_LED pin */
    GPIO_InitStructure.Pin   = LED_PIN[Led];
    GPIO_InitStructure.Mode  = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStructure.Pull  = GPIO_NOPULL;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
 
    HAL_GPIO_Init(LED2_GPIO_PORT, &GPIO_InitStructure);
    /* By default, turn off LED */
    HAL_GPIO_WritePin(LED2_GPIO_PORT, GPIO_InitStructure.Pin, GPIO_PIN_SET);
  }
  else
  {
    /* Initialize the IO functionalities */
    if (BSP_IO_Init() == IO_ERROR)
    {
      BSP_ErrorHandler();
    }
 
    /* By default, turn off LED */
    BSP_IO_WritePin(LED_PIN[Led], GPIO_PIN_SET);
 
    BSP_IO_ConfigPin(LED_PIN[Led],IO_MODE_OUTPUT);
  }
 
} 

[magene]

Excellent. For future readers, it's actually LED1 that is connected to the MFX chip and eventually uses the BSP_IO_WritePin function in the stm32l4r9i_discovery_io.c file which uses io_driver->WritePin(IO_I2C_ADDRESS, IO_Pin, 0) to actually set the state of the pin.