// This project controls the operation of a heater in a steam humidifier 
// deppending on the level of water in the tank.
// red = 20% full
// red & green = 40% full
// green = 60% full
// green & yellow = 80% full
// yellow = 100% full
// The pushbuttons are the respective levels of water in the tank
//while the red LED is the relay that will close the contacts of the heater
// https://wokwi.com/projects/341235931096810068

const int redButtonPin = 2;
const int greenButtonPin = 3;
const int yellowButtonPin = 4;
const int relay = 12;


void setup() {
  // declare the output and input pins:
  pinMode(redButtonPin, INPUT);
  pinMode(greenButtonPin, INPUT);
  pinMode(yellowButtonPin, INPUT);
  pinMode(relay, OUTPUT);
  // initialize serial communication:
  Serial.begin(9600);
}

void loop() {
  //declare variables and reading the values on the input pins:
  int redPin = digitalRead(redButtonPin);
  int greenPin = digitalRead(greenButtonPin);
  int yellowPin = digitalRead(yellowButtonPin);

// control the output when red is HIGH:
  if (redPin == HIGH)
    digitalWrite(relay, LOW);
    else if (redPin && greenPin == HIGH)
    digitalWrite(relay, LOW);
  // control the output when green is HIGH:
  if (greenPin == HIGH && redPin == LOW) {
    digitalWrite(relay, HIGH);
    }
   

  // control the output when yellow is HIGH, i.e @ 100% full
  if (yellowPin == HIGH) {
    digitalWrite(relay, HIGH);
  }

  if (redPin == HIGH && greenPin == HIGH)
    digitalWrite(relay, LOW);
  if (redPin == LOW && greenPin == LOW && yellowPin == LOW)
    digitalWrite(relay, LOW);
  
  
}