/*
  https://create.arduino.cc/projecthub/tarantula3/using-an-ldr-sensor-with-arduino-807b1c
  https://create.arduino.cc/projecthub/muhammed-shameel-k-v/how-to-use-a-relay-with-arduino-e04e3c
  https://docs.arduino.cc/built-in-examples/digital/BlinkWithoutDelay
*/

const int ledPin = 13;
const int relayPin = 9;
const int swtPin = 4;

int swtStatus;
unsigned long currentMillis;
unsigned long resetMillis;

void setup() {
  Serial.begin(9600);

  pinMode(ledPin, OUTPUT);
  pinMode(swtPin, INPUT);
  pinMode(relayPin, OUTPUT);
  swtStatus = 0;

  currentMillis = millis();
  resetMillis = millis();
}

void loop() {
  swtStatus = digitalRead(swtPin);

  // digitalWrite(ledPin, HIGH);
  if (swtStatus == 1) {
    resetMillis = millis();
    digitalWrite(relayPin, HIGH);
    delay(100);
  }

  currentMillis = millis();
  unsigned long delta = currentMillis - resetMillis;

  if (delta > (10 * 60 * 1000))             //10 mins x 60 sec x 1000 milliseconds
  {
    digitalWrite(relayPin, LOW);
  }
}