#include "stm32f4xx.h"
#include "stm32f4xx_rcc.c"
#include "stm32f4xx_gpio.c"
#include "stm32f4xx_exti.c"
#include "stm32f4xx_syscfg.c"
#include "LCD2x16.c"

int IRQcounter = 0;             // declare & initialize IRQ counter

void SWITCHinit (void)  {
GPIO_InitTypeDef        GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_3 | GPIO_Pin_4 | 
                                  GPIO_Pin_5 | GPIO_Pin_6;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_IN;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;
  GPIO_Init(GPIOE, &GPIO_InitStructure); 
}

void IRQinit_PE5 (void) {
//EXTIMode_TypeDef        EXTIMode_TypeStructure;
//EXTITrigger_TypeDef     EXTITrigger_TypeStructure;
EXTI_InitTypeDef        EXTI_InitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

  SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource5);
  SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource3);
  
  EXTI_InitStructure.EXTI_Line    = EXTI_Line5;
  EXTI_InitStructure.EXTI_Line   |= EXTI_Line3;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_InitStructure.EXTI_Mode    = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;  
  EXTI_Init(&EXTI_InitStructure); 
}

void main (void){   
  
  LCD_init();                            // init LCD
  LCD_string("IRQs at PE5:", 0x00);   // display title string

  SWITCHinit();
  IRQinit_PE5();
  NVIC_EnableIRQ(EXTI9_5_IRQn);   // Enable IRQ for ext. signals, lines 9 to 5
  NVIC_EnableIRQ(EXTI3_IRQn);   // Enable IRQ for ext. signals, lines 3
  
  while (1) {
    LCD_uInt16(IRQcounter,0x40,1);       // write IRQ count to LCD
    for (int i = 0; i<100000; i++) {};   // waste some time
  };
}

void EXTI9_5_IRQHandler (void)   {
  IRQcounter++;                          // do the actual work
  EXTI_ClearITPendingBit(EXTI_Line5);
  EXTI_ClearFlag(EXTI_Line5);
}

void EXTI3_IRQHandler (void)   {
  IRQcounter++;                          // do the actual work
  IRQcounter++;                          // do the actual work
  EXTI_ClearITPendingBit(EXTI_Line3);
  EXTI_ClearFlag(EXTI_Line3);
}