Main.c

#include "stm32f4xx.h"


/* Set variables used */
GPIO_InitTypeDef GPIO_InitStruct;
EXTI_InitTypeDef EXTI_InitStruct;
NVIC_InitTypeDef NVIC_InitStruct;

/* Configure pin to be interrupts */
void Configure_PA0(void)
{


    /* Enable clock for GPIOA */
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    /* Enable clock for SYSCFG */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

    /* Set pin as input */
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* Tell system that you will use PA0 for EXTI_Line0 */
    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0);

    /* PA0 is connected to EXTI_Line0 */
    EXTI_InitStruct.EXTI_Line = EXTI_Line0;
    /* Enable interrupt */
    EXTI_InitStruct.EXTI_LineCmd = ENABLE;
    /* Interrupt mode */
    EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
    /* Triggers on rising and falling edge */
    EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
    /* Add to EXTI */
    EXTI_Init(&EXTI_InitStruct);

    /* Add IRQ vector to NVIC */
    /* PA0 is connected to EXTI_Line0, which has EXTI0_IRQn vector */
    NVIC_InitStruct.NVIC_IRQChannel = EXTI0_IRQn;
    /* Set priority */
    NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0x00;
    /* Set sub priority */
    NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0x00;
    /* Enable interrupt */
    NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
    /* Add to NVIC */
    NVIC_Init(&NVIC_InitStruct);
}


void GPIOD_Initialize(void)
{
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD,ENABLE);

  GPIO_InitStruct.GPIO_Pin=GPIO_Pin_12|GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15;
  GPIO_InitStruct.GPIO_Mode=GPIO_Mode_OUT;
  GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz;
  GPIO_InitStruct.GPIO_OType=GPIO_OType_PP;
  GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_UP;

  GPIO_Init(GPIOD,&GPIO_InitStruct);
}

void EXTI0_IRQHandler(void)
{
    /* Make sure that interrupt flag is set */
    if (EXTI_GetITStatus(EXTI_Line0) != RESET)
    {
      GPIO_ResetBits(GPIOD,GPIO_Pin_12|GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15);
    /* Clear interrupt flag */
      EXTI_ClearITPendingBit(EXTI_Line0);
    }
}


void main()
{
  SystemInit();
  Configure_PA0();
  GPIOD_Initialize();

  GPIO_SetBits(GPIOD,GPIO_Pin_12|GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15);
  while(1);
}