🛠 STM32Cube HAL et BSP officiel : LED, bouton et accéléromètre avec détection automatique

Objective

Program the STM32F4DISCOVERY "from the source": the official STM32CubeF4 firmware contains a dedicated BSP (Board Support Package) for this board, located in Drivers/BSP/STM32F4-Discovery, with complete examples in Projects/STM32F4-Discovery/. You will use the BSP_LED_*, BSP_PB_*, and BSP_ACCELERO_* APIs — and above all, understand the automatic accelerometer detection, a hardware peculiarity of this board.

Hardware and Project

• 1 STM32F4DISCOVERY board, micro-USB cable on the ST-LINK/V2-A port
• STM32CubeIDE (or Makefile + arm-none-eabi-gcc) and the STM32CubeF4 package (GitHub repository STMicroelectronics/STM32CubeF4, cloned with --recursive — the board's BSP resides in the stm32f4discovery-bsp submodule)
• Define the USE_STM32F4_DISCO macro and add Drivers/BSP/STM32F4-Discovery, as well as Drivers/BSP/Components/lis302dl and lis3dsh, to the include path

The Hardware Trap: Two Accelerometers Depending on the Revision

The board was produced with two different MEMS on the same SPI1 bus: the LIS302DL on early boards, and the LIS3DSH on later ones (SCK PA5, MISO PA6, MOSI PA7, CS PE3, interrupts PE0/PE1). Code that assumes a single component fails silently on the other revision. The BSP solves this problem by reading the chip ID: use BSP_ACCELERO_Init and do not hardcode the component.

Complete Code

#include "stm32f4_discovery.h"
#include "stm32f4_discovery_accelerometer.h"

int main(void)
{
  int16_t xyz[3] = {0, 0, 0};

  HAL_Init;            /* SysTick/NVIC par defaut */
  SystemClock_Config;  /* 168 MHz depuis le quartz HSE 8 MHz */

  BSP_LED_Init(LED3);    /* LED3 = PD13 (orange) ; LED4/5/6 = PD12/14/15 */
  BSP_PB_Init(BUTTON_KEY, BUTTON_MODE_GPIO);  /* USER = PA0 */
  BSP_ACCELERO_Init;   /* auto-detecte LIS302DL vs LIS3DSH via chip ID */

  while (1)
  {
    BSP_LED_Toggle(LED3);
    BSP_ACCELERO_GetXYZ(xyz);   /* axes normalises entre revisions */
    if (BSP_PB_GetState(BUTTON_KEY) == GPIO_PIN_SET)
      BSP_LED_On(LED4);
    else
      BSP_LED_Off(LED4);
    HAL_Delay(100);
  }
}

What the BSP Hides from You (Useful to Know)

• The actual LED pins are defined in stm32f4_discovery.h: LED4=PD12 (green), LED3=PD13 (orange), LED5=PD14 (red), LED6=PD15 (blue).
• The button is named BUTTON_KEY in the BSP, although everyone calls it USER (PA0, active high).
• BSP_ACCELERO_GetXYZ returns axes oriented consistently between the two chips — this is exactly the normalization that your own driver should reimplement otherwise.

Expected Verification

The orange LED blinks at 5 Hz; the green LED stays on while USER is pressed. When tilting the board, the xyz values change (to be observed in the debugger, as the ST-LINK console is not wired on stock boards).

Common Errors

• Cloning STM32CubeF4 without --recursive: the BSP components (lis302dl/lis3dsh/cs43l22) are missing during compilation.
• Forgetting USE_STM32F4_DISCO: the BSP headers do not select the correct board.
• Writing a custom LIS302DL driver and discovering on a second board that the accelerometer is a LIS3DSH: read the chip ID, just like the BSP does.
• Looking for a joystick: unlike other Discovery kits, this one has only a USER button and a RESET button.