Using Potentiometers

Learn how to integrate potentiometers into your Arduino projects for precise analog control.

ARDUINO LESSONSElectronicsAnalog Input
S
Shaun Sosi
How to Use Potentiometers in Arduino Projects

Understanding Potentiometers

A potentiometer (or "pot" for short) is a versatile three-terminal component that functions as an adjustable voltage divider, allowing you to control voltage and current in your circuits with precision.

Potentiometer Structure and Usage
Understanding the structure and functionality of a potentiometer

Think of a Potentiometer Like This:

Imagine a water faucet where you can precisely control the flow. Just as the faucet handle controls water flow, the potentiometer's knob controls electrical flow, giving you smooth, precise control over voltage.

Get Your Arduino Kit

To follow along with this potentiometer tutorial:

Get Your Arduino Kit

The Elegoo Arduino kit includes potentiometers and all the components needed to build voltage-controlled projects.

View on Amazon
Arduino Kit

How Potentiometers Work

Core Concepts:

A potentiometer works by moving a wiper contact across a resistive element, creating an adjustable voltage divider that provides variable output based on position.

  1. Physical Structure

    • Three Terminals - Power (VCC), Ground (GND), and Wiper (Output)
    • Resistive Element - Fixed resistance track
    • Wiper - Moving contact that slides along the resistive element

  2. Electrical Operation

    • Voltage Division - Creates proportional voltage based on wiper position
    • Linear or Logarithmic - Different response curves for different applications
    • Smooth Control - Continuous adjustment within its range

Common Applications

Potentiometers are used in various applications:

  • Volume Control - Adjust audio levels in sound systems
  • Light Dimming - Control LED or lamp brightness
  • Position Sensing - Create position-based controls like joysticks
  • Circuit Tuning - Calibrate and adjust electronic circuits

Types of Potentiometers:

  • Rotary - Most common, turns like a knob
  • Slide - Linear movement, like audio mixing boards
  • Multi-turn - Precise adjustment over multiple rotations
  • Digital - Electronic version with discrete steps

Implementation with Arduino

Here's how to read and use a potentiometer with Arduino:

PotentiometerReader.ino
// Pin and variable declarations const int potPin = A0; // Potentiometer connected to analog pin A0 const int waitTime = 400; // Delay between readings int potValue; // Store the raw analog reading float voltage; // Store the converted voltage void setup() { // Configure pin and serial communication pinMode(potPin, INPUT); // Set potentiometer pin as input Serial.begin(9600); // Initialize serial communication } void loop() { // Read potentiometer value potValue = analogRead(potPin); // Convert to voltage (0-5V range) voltage = 5.0 / 1023.0 * potValue; // Display readings in Serial Monitor Serial.print("Raw Value: "); Serial.print(potValue); Serial.print(" | Voltage: "); Serial.print(voltage); Serial.println("V"); delay(waitTime); }

    Important Considerations:

    • Wiring - Ensure correct terminal connections (VCC, GND, and Wiper)
    • Noise - Consider adding a small capacitor for stability
    • Resolution - Remember you have 1024 distinct positions (0-1023)
    • Power Supply - Use a stable 5V source for consistent readings

    Practical Project Ideas

    Here are some projects you can build using potentiometers:

    • LED Dimmer - Control LED brightness
    • Servo Controller - Adjust servo motor position
    • Digital Instrument - Create musical controls
    • Game Controller - Build custom input devices
    LEDPotControl.ino
    const int potPin = A0; // Potentiometer input const int ledPin = 9; // LED output (PWM pin) int potValue; // Potentiometer reading int brightness; // LED brightness value void setup() { pinMode(potPin, INPUT); pinMode(ledPin, OUTPUT); } void loop() { // Read potentiometer potValue = analogRead(potPin); // Map pot value (0-1023) to LED range (0-255) brightness = map(potValue, 0, 1023, 0, 255); // Set LED brightness analogWrite(ledPin, brightness); delay(10); // Small delay for stability }

      Troubleshooting Tips

      Common issues and solutions:

      • Jumpy Readings - Add a smoothing capacitor (0.1µF)
      • Dead Spots - Check for worn-out potentiometer or poor connections
      • Inconsistent Values - Ensure stable power supply and good wiring
      • Non-linear Response - Consider using a different pot type (linear vs. logarithmic)

      Pro Tip:

      For more stable readings, implement a simple moving average:

      Smoothing.ino
      const int numReadings = 10; int readings[numReadings]; int readIndex = 0; int total = 0; // In loop(): total = total - readings[readIndex]; readings[readIndex] = analogRead(potPin); total = total + readings[readIndex]; readIndex = (readIndex + 1) % numReadings; int average = total / numReadings;

        Looking Ahead

        Now that you understand potentiometers:

        • Advanced Projects - Create complex control interfaces
        • Sensor Combinations - Combine with other sensors for rich interactions
        • Custom Controllers - Build specialized input devices
        • Calibration Tools - Develop precision measurement instruments

        Coming Up Next:

        Stay tuned for more exciting Arduino tutorials where we'll explore more components and create even more interesting projects!

        Connect With Me

        InstagramFollow me on InstagramGrowth HubVisit my websiteYouTubeSubscribe on YouTube

        Support Our Work

        Help us create more amazing content

        $

        Your contribution helps us create more amazing content. Thank you! 💖