Analog Temperature Sensor LED Alert on Arduino

This project allows you to use LED’s as a way to display temperature information.

Functional Parts in the Project:

• Arduino Uno – https://store.arduino.cc/usa/arduino-uno-rev3
• HC-SR204 Ultrasonic Sensor – https://amzn.to/31AGgYC
• Breadboard Kit – https://amzn.to/2Xih5ei
• Analog Temperature Sensor – https://amzn.to/2Rkkl3k
• 220 Ohm Resistors – https://amzn.to/2RiiMD9
• LED’s – https://amzn.to/2Rjhs2N

#define sensorPin  A0
#define greenLED 8
#define yellowLED 9
#define redLED 10

void setup()
{
  pinMode(greenLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(redLED, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
  int reading = analogRead(sensorPin);
  float voltage = reading * 5.0;
  voltage /= 1024.0;
  float temperatureC = (voltage - 0.5) * 100 ;
  float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;

  Serial.print(voltage); Serial.print(" volts  -  ");
  Serial.print(temperatureC); Serial.print(" degrees C  -  ");
  Serial.print(temperatureF); Serial.println(" degrees F");

  if (temperatureF >= 75) {
    digitalWrite(greenLED, LOW);
    digitalWrite(yellowLED, LOW);
    digitalWrite(redLED, HIGH);
  }
  else if (temperatureF >= 70 && temperatureF < 75) {
    digitalWrite(greenLED, LOW);
    digitalWrite(yellowLED, HIGH);
    digitalWrite(redLED, LOW);
  }
  else {
    digitalWrite(greenLED, HIGH);
    digitalWrite(yellowLED, LOW);
    digitalWrite(redLED, LOW);
  }

  delay(3000);
}