Arduino LED Temperature Indicator

Give this the parameters you want and the LEDs will light up according to the temperature cold blue, green fine, red hot

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Things used in this project

Hardware components

Arduino UNO

LED (generic)

Any color

Temperature Sensor

Jumper wires (generic)

Breadboard (generic)

Story

Step 1: Get Parts

Arduino Uno/Genuino

Breadboard

Jumper wires (generic)

3 220Ω resistors

3 LEDs (any color)

A temperature sensor (mine is an LM35, but most should work)

Step 2: Put Parts in Place

Follow Picture

Step 3: Wire It Up

Wire Set-up

Wire it up:

>Red LED goes to digital pin 4 through one of the resistors, and ground

>Green LED goes to digital pin 3 though a resistor, and ground

>Blue LED goes to digital pin 2 through a resistor, and ground

>Pin one (the pin on the left) of the temperature sensor goes to 5v

>Pin two (the pin in the middle) of the temperature sensor goes to analog pin A2

>pin three (the pin on the right) of the temperature sensor goes to ground

Step 4 : Put Code

Code

Code

const int hot = 87; //set hot parameter
const int cold = 75; //set cold parameter
void setup() {
pinMode(A2, INPUT); //sensor
pinMode(2, OUTPUT); //blue
pinMode(3, OUTPUT); //green
pinMode(4, OUTPUT); //red
Serial.begin(9600);
}
void loop() {
int sensor = analogRead(A2);
float voltage = (sensor / 1024.0) * 5.0;
float tempC = (voltage - .5) * 100;
float tempF = (tempC * 1.8) + 32;
Serial.print("temp: ");
Serial.print(tempF);
if (tempF < cold) { //cold
digitalWrite(2, HIGH);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
Serial.println(" It's Cold.");
}
else if (tempF >= hot) { //hot
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, HIGH);
Serial.println(" It's Hot.");
}
else { //fine
digitalWrite(2, LOW);
digitalWrite(3, HIGH);
digitalWrite(4, LOW);
Serial.println(" It's Fine.");
}
delay(10);
}

Arduino LED Temperature Indicator