Potentiometer with ESP32 DOIT DevKit v1 – Step-by-Step Tutorial

Introduction

A potentiometer (often called a pot) is a variable resistor that allows you to adjust resistance manually by rotating its knob. It is commonly used for volume control, brightness adjustment, and sensor calibration.

When connected to an ESP32, a potentiometer works as a voltage divider, giving an analog output that the ESP32 can read. In this tutorial, we’ll connect a potentiometer to GPIO 34 of ESP32 DOIT DevKit v1 and read its values in the Serial Monitor.

Components Required

• ESP32 DOIT DevKit v1
• Potentiometer (10kΩ recommended)
• Breadboard and jumper wires
• USB cable

Circuit Diagram

• Potentiometer VCC pin → 3.3V
• Potentiometer GND pin → GND
• Potentiometer middle pin (wiper) → GPIO 34

Arduino Code

// Potentiometer with ESP32 DOIT DevKit v1
// Pot connected to GPIO 34

int potPin = 34;   // Potentiometer connected to ADC pin
int potValue = 0;  // Variable to store Pot value

void setup() {
  Serial.begin(115200);  // Start Serial Monitor
}

void loop() {
  potValue = analogRead(potPin); // Read Pot value (0-4095)
  Serial.print("Potentiometer Value: ");
  Serial.println(potValue);
  delay(500); // Small delay for stability
}

Step-by-Step Code Explanation

Define Variables

int potPin = 34;
int potValue = 0;

• Assign GPIO 34 for potentiometer input.
• potValue will hold the sensor readings.

Setup Serial Monitor

Serial.begin(115200);

Starts serial communication to display potentiometer values.

Loop Function

potValue = analogRead(potPin);
Serial.println(potValue);

• Reads the potentiometer analog value (0–4095 range).
• Prints it in the Serial Monitor.
• Rotating the knob changes the value.

Output

• Open Serial Monitor (115200 baud).
• Rotate potentiometer knob → Values increase or decrease depending on direction.
• Left = Lower values (close to 0).
• Right = Higher values (close to 4095).

Real-Life Applications

• Volume Control → in radios, amplifiers.
• Light Dimmer → adjust brightness of LEDs.
• Servo Position Control → control angle of servos.
• Sensor Calibration → fine-tuning sensor thresholds.
• User Input Device → knob-based user interface in IoT projects.

Troubleshooting

Problem	Cause	Solution
Values always 0	Wrong wiring	Connect middle pin to GPIO 34
Values unstable	Loose connections	Use good breadboard/jumpers
Reads only max value	Wrong supply	Connect pot to 3.3V, not 5V
Serial not showing	Wrong baud rate	Set 115200 in Serial Monitor