How to use a Potentiometer with Arduino

Arduino, Electronics, Tutorials

In the world of robotics and electronics, sensors and input devices play a crucial role in allowing machines to interact with their environment. Among the simplest and most versatile components is the potentiometer — an inexpensive and reliable device that allows manual voltage adjustment.

🔍 What is a Potentiometer?

A potentiometer is a variable resistor with three terminals, whose resistance value can be adjusted by rotating a knob or sliding a control. It’s one of the most common input devices, often used in volume controls, light dimmers, joysticks, and various adjustment systems.

📑 How it Works

Inside a potentiometer is a resistive track and a wiper (a movable contact). By connecting the two outer pins to a reference voltage (typically 0V and 5V) and taking the signal from the center pin, you can get a variable voltage depending on the wiper’s position.

This voltage is read by the Arduino via an analog input pin and converted into a digital value using its built-in ADC (Analog to Digital Converter).

📝 Required Components

1 x Arduino Uno (or compatible board)
1 x potentiometer (10kΩ recommended)
Breadboard
Jumper wires

🔌 Wiring Diagram

Potentiometer	Arduino
Pin 1 (VCC)	5V
Pin 2 (OUT)	A0
Pin 3 (GND)	GND

📦 Complete Arduino Code

Here’s the code to read the potentiometer’s value and display it in the Serial Monitor:

				
					// Define the pin connected to the potentiometer
const int potPin = A0;

// Variable to store the analog reading
int potValue = 0;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
}

void loop() {
  // Read the analog value from the potentiometer
  potValue = analogRead(potPin);
  
  // Print the value to the Serial Monitor
  Serial.print("Potentiometer Value: ");
  Serial.println(potValue);
  
  // Wait 200 milliseconds before the next reading
  delay(200);
}

🔎 Breaking down the Code

Let’s review the code section by section:

Variable Declarations

We define:

potPin → the analog pin connected to the potentiometer.
potValue → a variable to hold the reading.

				
					const int potPin = A0;
int potValue = 0;

Setup Function

				
					void setup() {
  Serial.begin(9600);
}

In the setup() function, which runs once when the board is powered on:

We initialize serial communication at 9600 baud, necessary for sending data to the computer and viewing it in the Arduino IDE Serial Monitor.

Main Loop

				
					potValue = analogRead(potPin);

This reads the voltage from the analog pin A0. The analogRead() function returns an integer between 0 and 1023, where:

0 represents 0V
1023 represents 5V

				
					Serial.print("Potentiometer Value: ");
Serial.println(potValue);

Sends the value to the Serial Monitor, preceded by a descriptive label.

				
					delay(200);

Pauses the program for 200 milliseconds before the next reading, making the data stream easier to follow.

🖥️ Viewing the Data

To monitor the values in real-time:

Upload the code to your Arduino board.
Open the Serial Monitor from the Arduino IDE (Tools > Serial Monitor).
Set the baud rate to 9600.
Turn the potentiometer knob and watch the values change from 0 to 1023.