Serial.print('IR Neg Pin = ') // Display 'A3 = ' Serial.print(volts(IRMP)) // Display measured A3 volts Serial.print('IR Pos Pin = ') // Display 'A3 = ' the loop function runs over and over again until power down or reset the setup function runs once when you press reset or power the boardĮIFR = bit(INTF5) // clear flag for interrupt 0ĮIFR = bit(INTF4) // clear flag for interrupt 1ĮIFR = bit(INTF3) // clear flag for interrupt 1ĮIFR = bit(INTF2) // clear flag for interrupt 1ĮIFR = bit(INTF1) // clear flag for interrupt 1ĮIFR = bit(INTF0) // clear flag for interrupt 1ĪttachInterrupt(digitalPinToInterrupt(Trans_pin_CL),ĪttachInterrupt(digitalPinToInterrupt(Trans_pin_CC),ĪttachInterrupt(digitalPinToInterrupt(Trans_pin_CR), Is there some reason you need to use interrupts rather than polling? Have you written a simple sketch that just displays the state of those pins to make sure they are actually changing when the IR is blocked?Īlso, it sounds like a rather simple application. Is there a way to get the same functionality as the other two pins?Īrduino Mega 2560 Rev3 - Arduino Official StoreĬan't really help much without seeing your sketch. Is there something different about these two pins that prevents them from being used like the other four. Not sure what to make of it other than these pins can't have a low setting? For pins 20 (SDA) and 21 (SCL), it does not.įrom looking at the interactive board viewer, these two pins appear to be a little different. For pins 2,3,18 and 19, the setup works as expected. When the voltage rises, an interrupt routine is executed. When the IR light which shines on the phototransistor is blocked, the transistor causes an open circuit and the voltage at the pin rises. I am using an IR phototransistor and an IR LED as motion detector.

Arduino mega 2560 pin descriptions