const int button1 = 2;
const int button2 = 9;
const int button3 = 10;

const int redLED = A3;
const int yellowLED = A4;
const int greenLED = A5;

void setup() {
  pinMode(button1, INPUT_PULLUP);
  pinMode(button2, INPUT_PULLUP);
  pinMode(button3, INPUT_PULLUP);

  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  
  Serial.begin(9600); // Initialize Serial Monitor
}

void loop() {
  int buttonState1 = digitalRead(button1);
  int buttonState2 = digitalRead(button2);
  int buttonState3 = digitalRead(button3);

  if (buttonState1 == LOW) {  // FULL TANK
    digitalWrite(redLED, LOW);     // OFF
    digitalWrite(yellowLED, LOW);  // OFF
    digitalWrite(greenLED, HIGH);  // ON
    Serial.println("FULL TANK");
  } 
  else if (buttonState2 == LOW) {  // MEDIUM TANK
    digitalWrite(redLED, LOW);    // OFF
    digitalWrite(yellowLED, HIGH); // ON
    digitalWrite(greenLED, LOW);  // OFF
    Serial.println("MEDIUM TANK");
  } 
  else if (buttonState3 == LOW) {  // EMPTY TANK
    digitalWrite(redLED, HIGH);   // ON
    digitalWrite(yellowLED, LOW); // OFF
    digitalWrite(greenLED, LOW);  // OFF
    Serial.println("EMPTY TANK");
  } 
  else {  // NO BUTTON PRESSED
    digitalWrite(redLED, LOW);   // OFF
    digitalWrite(yellowLED, LOW); // OFF
    digitalWrite(greenLED, LOW);  // OFF
  }

  delay(200);
}