Arduino Variable Resistor (Potentiometer) Control

Introduction

A variable resistor (potentiometer) allows you to control voltage levels manually. In this project, we use a potentiometer to control LED brightness using Arduino PWM.

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Components Required

• Arduino Uno R3
• Potentiometer (10K)
• LED
• 220Ω resistor
• Breadboard

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Circuit

Potentiometer connections:

• Left pin → 5V
• Right pin → GND
• Middle pin → A0

LED connections:

• LED positive → Pin 9
• LED negative → 220Ω resistor → GND

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Arduino Code

int potPin = A0;
int ledPin = 9;void setup() {
  pinMode(ledPin, OUTPUT);
}void loop() {
  int value = analogRead(potPin);
  int brightness = map(value, 0, 1023, 0, 255);  analogWrite(ledPin, brightness);
}

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How It Works

• analogRead() reads the potentiometer value
• The value ranges from 0–1023
• map() converts it to 0–255
• analogWrite() controls LED brightness using PWM

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Conclusion

This project demonstrates:

• Analog input reading
• PWM output control
• Variable brightness adjustment

It is a fundamental Arduino project used in motor control, dimmers, and sensor systems.