Arduino Nano ESP32 - Potentiometer LED

This tutorial instructs you how to use Arduino Nano ESP32 with the potentiometer to change the brightness of LED.

Hardware Preparation

1×Arduino Nano ESP32
1×USB Cable Type-C
1×Potentiometer
1×LED
1×220 ohm resistor
1×Breadboard
1×Jumper Wires
1×(Optional) DC Power Jack
1×(Recommended) Screw Terminal Adapter for Arduino Nano

Or you can buy the following sensor kit:

1×DIYables Sensor Kit 30 types, 69 units
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Overview of LED and Potentiometer

We have specific tutorials about LED and potentiometer. Each tutorial contains detailed information and step-by-step instructions about hardware pinout, working principle, wiring connection to ESP32, Arduino Nano ESP32 code... Learn more about them at the following links:

Wiring Diagram

The wiring diagram between Arduino Nano ESP32 and Rotary Potentiometer LED

This image is created using Fritzing. Click to enlarge image

How To Program

  • Reads the input on analog pin (value between 0 and 4095)
int analogValue = analogRead(36); // GPIO36 (ADC0)
  • Scales it to brightness (value between 0 and 255)
int brightness = map(analogValue, 0, 4095, 0, 255);
  • Sets the brightness LED
analogWrite(LED_PIN, brightness);

Arduino Nano ESP32 Code

/* * This Arduino Nano ESP32 code was developed by newbiely.com * * This Arduino Nano ESP32 code is made available for public use without any restriction * * For comprehensive instructions and wiring diagrams, please visit: * https://newbiely.com/tutorials/arduino-nano-esp32/arduino-nano-esp32-potentiometer-led */ #define POTENTIOMETER_PIN A0 // The Arduino Nano ESP32 pin connected to Potentiometer pin #define LED_PIN D3 // The Arduino Nano ESP32 pin connected to LED's pin // 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 4095) int analogValue = analogRead(POTENTIOMETER_PIN); // scales it to brightness (value between 0 and 255) int brightness = map(analogValue, 0, 4095, 0, 255); // sets the brightness LED that connects to pin 3 analogWrite(LED_PIN, brightness); // print out the value Serial.print("Analog value = "); Serial.print(analogValue); Serial.print(" => brightness = "); Serial.println(brightness); delay(100); }

Detailed Instructions

How to open serial monitor on Arduino IDE
  • Rotate the potentiometer
  • See the LED fading
  • See the result on Serial Monitor. It looks like the below:
COM6
Send
Analog value = 6 => brightness = 1 Analog value = 34 => brightness = 8 Analog value = 89 => brightness = 22 Analog value = 149 => brightness = 37 Analog value = 214 => brightness = 53 Analog value = 297 => brightness = 74 Analog value = 365 => brightness = 90 Analog value = 431 => brightness = 107 Analog value = 510 => brightness = 127 Analog value = 589 => brightness = 146 Analog value = 695 => brightness = 173 Analog value = 790 => brightness = 196 Analog value = 970 => brightness = 241 Analog value = 996 => brightness = 248 Analog value = 1018 => brightness = 253 Analog value = 4095 => brightness = 255
Autoscroll Show timestamp
Clear output
9600 baud  
Newline  

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