// Arduino Temperature Gauge
// Written by Josh Leyte-Jammu
// Written on 2015 02 19

// Declare program variables
const int tempSensorPin = A0;  // Declare the analog pin that reads the temperature sensor

// Declare program constants
const float setTempC = 21.0; // Degrees Celsius set to 21 (general room temperature)


void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);  // Open a serial port at 9600 bits per second.
  
  for(int pinNumber = 2; pinNumber<5; pinNumber++){  // Run through digital pins 2, 3, and 4 sequentially.
    pinMode(pinNumber,OUTPUT);
    digitalWrite(pinNumber,LOW);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  int tempSensorVal = analogRead(tempSensorPin);
  
  float voltage = (tempSensorVal/1024.0)*5.0;  // Convert the ADC reading into voltage. Voltage on the pin will be between 0 and 5 Volts.
  
  Serial.print("The temperature in degrees Celcius is ");
  float tempC = (voltage - 0.5)*100;  // Convert the calculated voltage into degrees Celsius.
  Serial.println(tempC);  // Print the temperature in degrees Celsius. Create a new line after.
  
  if(tempC < setTempC-1.5){
    digitalWrite(2,HIGH); // Blue LED ON
    digitalWrite(3,LOW);  // Green LED OFF
    digitalWrite(4,LOW);  // Red LED OFF
  }else if(tempC >= setTempC-1.5 && tempC < setTempC-0.5){
    digitalWrite(2,HIGH); // Blue LED ON
    digitalWrite(3,HIGH); // Green LED ON
    digitalWrite(4,LOW);  // Red LED OFF
  }else if(tempC >= setTempC-0.5 && tempC < setTempC+0.5){
    digitalWrite(2,LOW);  // Blue LED OFF
    digitalWrite(3,HIGH); // Green LED ON
    digitalWrite(4,LOW);  // Red LED OFF
  }else if(tempC >= setTempC+0.5 && tempC < setTempC+1.5){
    digitalWrite(2,LOW);  // Blue LED OFF
    digitalWrite(3,HIGH); // Green LED ON
    digitalWrite(4,HIGH); // Red LED ON
  }else if(tempC > setTempC+1.5){
    digitalWrite(2,LOW);  // Blue LED OFF
    digitalWrite(3,LOW);  // Green LED OFF
    digitalWrite(4,HIGH); // Red LED ON
  }
  delay(1000); // Delay by one second.

}