Arduino - Potentiometer fade LED

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

Hardware Required

1	×	Arduino UNO or Genuino UNO
1	×	USB 2.0 cable type A/B (for USB-A PC)
1	×	USB 2.0 cable type C/B (for USB-C PC)
1	×	Potentiometer
1	×	(Alternative) Potentiometer Kit
1	×	(Alternative) Potentiometer Module with Knob
1	×	LED
1	×	220 ohm resistor
1	×	Breadboard
1	×	Jumper Wires
1	×	(Recommended) Screw Terminal Block Shield for Arduino Uno
1	×	(Recommended) Breadboard Shield For Arduino Uno
1	×	(Recommended) Enclosure For Arduino Uno

Or you can buy the following sensor kits:

1	×	DIYables Sensor Kit (30 sensors/displays)
1	×	DIYables Sensor Kit (18 sensors/displays)

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Additionally, some links direct to products from our own brand, DIYables.

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

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How To Program

Reads the input on analog pin A0 (value between 0 and 1023)

int analogValue = analogRead(A0);

Scales it to brightness (value between 0 and 255)

int brightness = map(analogValue, 0, 1023, 0, 255);

Sets the brightness LED that connects to pin 3

analogWrite(LED_PIN, brightness);

Arduino Code

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-potentiometer-fade-led */ int LED_PIN = 3; // the PWM pin the LED is attached to // the setup routine runs once when you press reset: void setup() { // initialize serial communication at 9600 bits per second: Serial.begin(9600); // declare LED pin to be an output: pinMode(LED_PIN, OUTPUT); } // the loop routine runs over and over again forever: void loop() { // reads the input on analog pin A0 (value between 0 and 1023) int analogValue = analogRead(A0); // scales it to brightness (value between 0 and 255) int brightness = map(analogValue, 0, 1023, 0, 255); // sets the brightness LED that connects to pin 3 analogWrite(LED_PIN, brightness); // print out the value Serial.print("Analog: "); Serial.print(analogValue); Serial.print(", Brightness: "); Serial.println(brightness); delay(100); }

Quick Steps

Copy the above code and open with Arduino IDE
Click Upload button on Arduino IDE to upload code to Arduino
Open Serial Monitor
Rotate the potentiometer
See the LED
See the result on Serial Monitor

COM6

Send

Analog: 6, Brightness: 1 Analog: 34, Brightness: 8 Analog: 89, Brightness: 22 Analog: 149, Brightness: 37 Analog: 214, Brightness: 53 Analog: 297, Brightness: 74 Analog: 365, Brightness: 90 Analog: 431, Brightness: 107 Analog: 510, Brightness: 127 Analog: 589, Brightness: 146 Analog: 695, Brightness: 173 Analog: 790, Brightness: 196 Analog: 970, Brightness: 241 Analog: 996, Brightness: 248 Analog: 1018, Brightness: 253 Analog: 1023, Brightness: 255

Autoscroll Show timestamp

Clear output

9600 baud

Newline

Video Tutorial

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LED on Commercial Products

Small LEDs usually are used to indicate the status of devices. For examples:

Big LEDs usually are used for lighting. They can be combined into groups. For examples:

Potentiometer on Commercial Products

Digital Oscilloscope

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