Arduino - Potentiometer Triggers LED

In a previous tutorial , We have learned how to change the brightness of LED according to the potentiometer's output value. In this tutorial, We are going to learn how to:

Hardware Required

1×Arduino UNO or Genuino UNO
1×USB 2.0 cable type A/B
1×Potentiometer
1×LED
1×220 ohm resistor
1×Breadboard
4×Jumper Wires
Please note: These are affiliate links. If you buy the components through these links, We may get a commission at no extra cost to you. We appreciate it.

About LED and Potentiometer

If you do not know about LED and potentiometer (pinout, how it works, how to program ...), learn about them in the following tutorials:

Wiring Diagram

Arduino Potentiometer LED Wiring Diagram

Image is developed using Fritzing. Click to enlarge image

Arduino Code - Analog Threshold

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-potentiometer-triggers-led */ // constants won't change const int POTENTIOMETER_PIN = A0; // Arduino pin connected to Potentiometer pin const int LED_PIN = 3; // Arduino pin connected to LED's pin const int ANALOG_THRESHOLD = 500; void setup() { pinMode(LED_PIN, OUTPUT); // set arduino pin to output mode } void loop() { int analogValue = analogRead(POTENTIOMETER_PIN); // read the input on analog pin if(analogValue > ANALOG_THRESHOLD) digitalWrite(LED_PIN, HIGH); // turn on LED else digitalWrite(LED_PIN, LOW); // turn off LED }

Quick Steps

  • Connect Arduino to PC via USB cable
  • Open Arduino IDE, select the right board and port
  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
  • Arduino IDE Upload Code
  • Rotate the potentiometer
  • See the change of LED's state

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Arduino Code - Voltage Threshold

Potentiometer's analog value is converted to voltage value, and then compared to voltage threshold to triggers LED

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-potentiometer-triggers-led */ // constants won't change const int POTENTIOMETER_PIN = A0; // Arduino pin connected to Potentiometer pin const int LED_PIN = 3; // Arduino pin connected to LED's pin const float VOLTAGE_THRESHOLD = 2.5; // Voltages void setup() { pinMode(LED_PIN, OUTPUT); // set arduino pin to output mode } void loop() { int analogValue = analogRead(POTENTIOMETER_PIN); // read the input on analog pin float voltage = floatMap(analogValue, 0, 1023, 0, 5); // Rescale to potentiometer's voltage if(voltage > VOLTAGE_THRESHOLD) digitalWrite(LED_PIN, HIGH); // turn on LED else digitalWrite(LED_PIN, LOW); // turn off LED } float floatMap(float x, float in_min, float in_max, float out_min, float out_max) { return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; }

Video Tutorial

We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.

The Best Arduino Starter Kit

※ OUR MESSAGES