Interrupt Pin Ceased Firing/Sleep Mode Issues

Howdy, I am fairly new to programming with Arduino, but I am undertaking the project of operating a relay when an external short is detected. I decided to use the SLEEP_MODE_PWR_DOWN functionality in the avr/sleep.h library to save on battery life, essentially waking up the Arduino and activating the relay whenever the interrupt pin detects a signal from the short. However, after implementing the library my code has stopped working consistently. The interrupt pin (3) will activate for a seemingly random number of shorts and then proceed to stop activating when shorted all of a sudden. The digital pin output received when the system is working (short is detected properly) is 0, but the system will return a 1 value on occasion, although this mistake will not always cause the system to stop working. Another clue may be that the interrupt message I programmed to activate whenever the interrupt pin fires can pop up twice, even when the digital pin signal is not displayed. Any help decoding this error would be greatly appreciated.

#include <avr/sleep.h>

int relay = 2; // Relay Control Pin
int floaty = 3; // Sensor/Interrupt pin
int comp; // Comparison Value

void setup()
  Serial.begin(9600); // Serial for Debuging
  pinMode(relay, OUTPUT);
  pinMode(floaty, INPUT_PULLUP);


void wakeUp()
  Serial.println("Interrupt Activated");

void Going_To_Sleep()
  attachInterrupt(digitalPinToInterrupt(floaty), wakeUp, LOW);
  digitalWrite(LED_BUILTIN, LOW);
  digitalWrite(LED_BUILTIN, HIGH);

void loop()
  comp = digitalRead(floaty);
  Serial.print("Reading =");

  if (comp == 1)
    digitalWrite(relay, HIGH);
    digitalWrite(relay, LOW);

  else if (comp == 0)


Post a schematic, not a frizzy picture as it does not show all connections and is hard to see. Also post links to technical information on the hardware items.

Relay Operation Diagram.pdf (176.8 KB)

That just saved a lot of words. Your protection diode from collector to ground will always conduct so the relay will not release. The cathode band should be connected to the +5 and you will be all set.

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