Reading a Potentiometer with ADC

The Hardware Setup

A potentiometer is a variable resistor with three legs: two outer legs connect to power and ground, and the middle "wiper" leg outputs a voltage somewhere between the two, depending on the knob position. We'll read that wiper voltage on an ADC-capable GPIO.

Stick to ADC1 pins (GPIO 1–10 on most ESP32-S3 boards) for this project — ADC2 shares hardware with Wi-Fi and can give unreliable readings while the radio is active.

The Arduino Source Code

The ESP32-S3's ADC supports up to 12-bit resolution, giving readings from 0 to 4095. This code reads the raw value and converts it into an actual voltage (0–3.3V) for the Serial Monitor.

// ESP32-S3 Potentiometer + ADC Tutorial - CircuitHub.pro
#include <Arduino.h>

const int POT_PIN = 1; // ADC1_CH0

void setup() {
  Serial.begin(115200);
  analogReadResolution(12); // Use the full 0-4095 range
}

void loop() {
  int raw = analogRead(POT_PIN);
  float voltage = (raw / 4095.0) * 3.3;

  Serial.print("Raw ADC: ");
  Serial.print(raw);
  Serial.print("   Voltage: ");
  Serial.print(voltage, 2);
  Serial.println("V");

  delay(200);
}

Required Components

Simple, cheap parts — a great one to keep in your basic toolkit: