Arduino Nano - Potentiometer fade LED

This tutorial instructs you how to use Arduino Nano to adjust the brightness of the LED based on the output of the potentiometer.

Hardware Preparation

1×Arduino Nano
1×USB A to Mini-B USB cable
1×220 ohm resistor
1×Jumper Wires
1×(Optional) 9V Power Adapter for Arduino Nano
1×(Recommended) Screw Terminal Adapter for Arduino Nano

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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Overview of LED and Potentiometer

If you are unfamiliar with LED and potentiometer (including pinout, operation, and programming), the following tutorials can help:

Wiring Diagram

The wiring diagram between Arduino Nano and Rotary Potentiometer LED

This image is created using Fritzing. Click to enlarge image

How To Program

  • Gets the value from analog pin A0, which is a range of 0 to 1023.
int analog_value = analogRead(A0);
  • Adjusts the brightness to a value between 0 and 255.
int brightness = map(analog_value, 0, 1023, 0, 255);
  • Sets the LED connected to pin 3 to the brightness.
analogWrite(LED_PIN, brightness);

Arduino Nano Code

/* * This Arduino Nano code was developed by * * This Arduino Nano code is made available for public use without any restriction * * For comprehensive instructions and wiring diagrams, please visit: * */ int LED_PIN = 3; // The PWM pin the LED is attached to // The setup function runs once on reset or power-up void setup() { // Initialize the Serial to communicate with the Serial Monitor. Serial.begin(9600); // declare LED pin to be an output: pinMode(LED_PIN, OUTPUT); } // The loop function repeats indefinitely. void loop() { // reads the input on analog pin A0 (value between 0 and 1023) int analog_value = analogRead(A0); // scales it to brightness (value between 0 and 255) int brightness = map(analog_value, 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(analog_value); Serial.print(", Brightness: "); Serial.println(brightness); delay(100); }

Detailed Instructions

  • Copy the code above and open it with the Arduino IDE.
  • Click the Upload button on the Arduino IDE to compile and upload the code to the Arduino Nano.
  • Open the Serial Monitor.
  • Turn the potentiometer.
  • Check out the LED.
  • Check out the result on the Serial Monitor.
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
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