Pro Micro interrupts 0 & 1 work, 2 - 4 do not

Hey all,

I'm working with a Sparkfun ProMicro 5V 16 MHz, which is essentially a regular micro. I have an IR sensor that outputs high or low, depending on the color of the paper it's in front of. The problem is that I can get it to trigger an interrupt on pins 2 or 3 (int.0 or int.1), but using the same setup and program, I can't get interrupt 2, 3, or 4 to work. According to the AttachInterrupts page (attachInterrupt() - Arduino Reference) the Leonardo and ProMicro should support interrupts on pins 0, 1, and 7 as well. Am I missing something? My program is as follows, I just changed the interrupt number to test:

int flag = 0;

void setup() {
  attachInterrupt(4, test, CHANGE);

}

void test(){
  if (flag == 0){
    flag = 1;
  }
  else {
    flag = 0;
  }
}

void loop() {

if (flag == 1){
  digitalWrite(17, HIGH);
}
else {
  digitalWrite(17, LOW);
}

}

Any insight?

May be you need:
volatile int flag = 0;

Good catch, I'll give that a shot. Unfortunately this program works with interrupts 0 and 1, which makes me think that this may not be the problem. Has anyone run into this issue with the micros or leonardos? I checked the schematics, they have the same pin out (D7 is the same on both)

If you look at the WInterrupts.c attachInterrupt() function, it only support Interrupt 0 to 3 and not 4

void attachInterrupt(uint8_t interruptNum, void (*userFunc)(void), int mode) {
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) {
    intFunc[interruptNum] = userFunc;
    
    // Configure the interrupt mode (trigger on low input, any change, rising
    // edge, or falling edge).  The mode constants were chosen to correspond
    // to the configuration bits in the hardware register, so we simply shift
    // the mode into place.
      
    // Enable the interrupt.
      
    switch (interruptNum) {
#if defined(__AVR_ATmega32U4__)
	// I hate doing this, but the register assignment differs between the 1280/2560
	// and the 32U4.  Since avrlib defines registers PCMSK1 and PCMSK2 that aren't 
	// even present on the 32U4 this is the only way to distinguish between them.
	case 0:
		EICRA = (EICRA & ~((1<<ISC00) | (1<<ISC01))) | (mode << ISC00);
		EIMSK |= (1<<INT0);
		break;
	case 1:
		EICRA = (EICRA & ~((1<<ISC10) | (1<<ISC11))) | (mode << ISC10);
		EIMSK |= (1<<INT1);
		break;	
    case 2:
        EICRA = (EICRA & ~((1<<ISC20) | (1<<ISC21))) | (mode << ISC20);
        EIMSK |= (1<<INT2);
        break;
    case 3:
        EICRA = (EICRA & ~((1<<ISC30) | (1<<ISC31))) | (mode << ISC30);
        EIMSK |= (1<<INT3);
        break;
#elif defined(EICRA) && defined(EICRB) && defined(EIMSK)
    case 2:
      EICRA = (EICRA & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      EIMSK |= (1 << INT0);
      break;
    case 3:
      EICRA = (EICRA & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      EIMSK |= (1 << INT1);
      break;
    case 4:
      EICRA = (EICRA & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      EIMSK |= (1 << INT2);
      break;
    case 5:
      EICRA = (EICRA & ~((1 << ISC30) | (1 << ISC31))) | (mode << ISC30);
      EIMSK |= (1 << INT3);
      break;
    case 0:
      EICRB = (EICRB & ~((1 << ISC40) | (1 << ISC41))) | (mode << ISC40);
      EIMSK |= (1 << INT4);
      break;
    case 1:
      EICRB = (EICRB & ~((1 << ISC50) | (1 << ISC51))) | (mode << ISC50);
      EIMSK |= (1 << INT5);
      break;
    case 6:
      EICRB = (EICRB & ~((1 << ISC60) | (1 << ISC61))) | (mode << ISC60);
      EIMSK |= (1 << INT6);
      break;
    case 7:
      EICRB = (EICRB & ~((1 << ISC70) | (1 << ISC71))) | (mode << ISC70);
      EIMSK |= (1 << INT7);
      break;
#else		
    case 0:
    #if defined(EICRA) && defined(ISC00) && defined(EIMSK)
      EICRA = (EICRA & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      EIMSK |= (1 << INT0);
    #elif defined(MCUCR) && defined(ISC00) && defined(GICR)
      MCUCR = (MCUCR & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      GICR |= (1 << INT0);
    #elif defined(MCUCR) && defined(ISC00) && defined(GIMSK)
      MCUCR = (MCUCR & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      GIMSK |= (1 << INT0);
    #else
      #error attachInterrupt not finished for this CPU (case 0)
    #endif
      break;

    case 1:
    #if defined(EICRA) && defined(ISC10) && defined(ISC11) && defined(EIMSK)
      EICRA = (EICRA & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      EIMSK |= (1 << INT1);
    #elif defined(MCUCR) && defined(ISC10) && defined(ISC11) && defined(GICR)
      MCUCR = (MCUCR & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      GICR |= (1 << INT1);
    #elif defined(MCUCR) && defined(ISC10) && defined(GIMSK) && defined(GIMSK)
      MCUCR = (MCUCR & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      GIMSK |= (1 << INT1);
    #else
      #warning attachInterrupt may need some more work for this cpu (case 1)
    #endif
      break;
    
    case 2:
    #if defined(EICRA) && defined(ISC20) && defined(ISC21) && defined(EIMSK)
      EICRA = (EICRA & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      EIMSK |= (1 << INT2);
    #elif defined(MCUCR) && defined(ISC20) && defined(ISC21) && defined(GICR)
      MCUCR = (MCUCR & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      GICR |= (1 << INT2);
    #elif defined(MCUCR) && defined(ISC20) && defined(GIMSK) && defined(GIMSK)
      MCUCR = (MCUCR & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      GIMSK |= (1 << INT2);
    #endif
      break;
#endif
    }
  }
}

See my thread on SparkFun:

https://forum.sparkfun.com/viewtopic.php?f=32&t=35847&p=160331#p160331

I had to use C programming from the datasheet, but I got interrupt 6 working (pin 7). I'm sure I could modify it to work with the others as well