const int thermistor = A0;  // declare analog pin for sensor
const int green_LED = 1;    // declare pins for LEDs
const int white_LED = 2;
const int orange_LED = 3;
const int red_LED = 4;
int sensorValue;            // for storing the sensor data


void setup() {
  // put your setup code here, to run once:
  pinMode(thermistor, INPUT_PULLUP); // activate built in resistor
  pinMode(green_LED, OUTPUT);        // assign LEDs as outputs
  pinMode(white_LED, OUTPUT);
  pinMode(orange_LED, OUTPUT);
  pinMode(red_LED, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:

  // Note that resistance gets smaller w/ increased temperature
  sensorValue = analogRead(thermistor);   // 0-1024 for input voltage 0v-5v
  if (sensorValue <= 714) {                // room temp is ~713
    digitalWrite(green_LED, HIGH);        // turn the green LED on, all others off
    digitalWrite(white_LED, LOW);
    digitalWrite(orange_LED, LOW);
    digitalWrite(red_LED, LOW);
  }
      else if (sensorValue > 714 and sensorValue <= 716) {  // warm
      digitalWrite(green_LED, LOW);
      digitalWrite(white_LED, HIGH);      // turn the white LED on, all others off
      digitalWrite(orange_LED, LOW);
      digitalWrite(red_LED, LOW);
    }
    else if (sensorValue > 716 and sensorValue <= 718) {    // warmer
      digitalWrite(green_LED, LOW);
      digitalWrite(white_LED, LOW);
      digitalWrite(orange_LED, HIGH);     // turn the orange LED on, all others off
      digitalWrite(red_LED, LOW);
    }
    else if (sensorValue > 718) {                           // warmest
      digitalWrite(green_LED, LOW);
      digitalWrite(white_LED, LOW);
      digitalWrite(orange_LED, LOW);
      digitalWrite(red_LED, HIGH);        // turn the red LED on, all others off
    }
    else {                                // turn all lights on if there is an issue
      digitalWrite(green_LED, HIGH);
      digitalWrite(white_LED, HIGH);
      digitalWrite(orange_LED, HIGH);
      digitalWrite(red_LED, HIGH);
    }
  delay(100);
}