Analog Joystick: ESP32 Wiring and Axis Readings

Before you start

Board and software

Classic ESP32-WROOM-32/32E DevKit with these GPIOs exposed and unused. Arduino IDE 2.x; esp32 by Espressif Systems 3.x (API review baseline 3.3.2, not a latest-version claim). Select the exact board or ESP32 Dev Module for a generic WROOM board. Other ESP32 families need their own pin map. Serial Monitor: 115200 baud.

Hardware assumption

A passive two-potentiometer joystick breakout with VRx, VRy and a normally open SW contact to GND, documented to operate at 3.3 V. No model, resistance or physical header order is inferred. This is not an I2C/Qwiic joystick.

Prerequisites and parts

First complete Arduino IDE setup and Blink. Joystick, breadboard and wires; verify the breakout has no 5 V-only electronics or pull-ups.

Expected result

X and Y readings change as the stick moves; SW reads LOW when pressed. Center and end readings vary, so calibrate your own module.

Verification status

Reviewed against the technical references below. Not compiled for an ESP32 or tested on hardware in this update. The approved product-style illustration identifies the family; follow documented terminal labels and the logical wiring diagram, not its rendered pin positions.

Overview

02Technical Specifications

Arduino library: No additional library; Arduino-ESP32 ADC and GPIO APIs

03Pinout

• VCC / + Potentiometer supply ESP32 3.3 V Only for a module documented for this passive 3.3 V use.
• GND / - Reference ESP32 GND Shared reference for both axes and switch.
• VRx / X X wiper GPIO32 ADC1 input; never a 5 V wiper.
• VRy / Y Y wiper GPIO33 ADC1 input; orientation may reverse an axis.
• SW Push switch GPIO27 with INPUT_PULLUP Assumes switch closes to GND. GPIO34–39 lack internal pull resistors on classic ESP32.

04Wiring Diagram

VCC to 3.3 V, GND to GND, VRx to GPIO32, VRy to GPIO33 and SW to GPIO27. This example prints raw axis readings and the instantaneous switch level.

Open wiring diagram at full size (new tab)

1. 1

   With power disconnected, verify the module circuit/labels and its 3.3 V suitability.

2. 2

   Connect only the five named signals, then select the classic WROOM board profile.

3. 3

   Upload and open Serial Monitor; move each axis separately and press the stick.

4. 4

   Observe the actual center and extremes before choosing a dead zone or mapping values to motion.

Wiring and matching Arduino code

Raw axis and push-switch readout

VCC to 3.3 V, GND to GND, VRx to GPIO32, VRy to GPIO33 and SW to GPIO27. This example prints raw axis readings and the instantaneous switch level.

#include <Arduino.h>
constexpr uint8_t X_PIN = 32, Y_PIN = 33, SW_PIN = 27;
void setup() {
  Serial.begin(115200);
  pinMode(SW_PIN, INPUT_PULLUP);
  analogReadResolution(12);
  analogSetPinAttenuation(X_PIN, ADC_11db);
  analogSetPinAttenuation(Y_PIN, ADC_11db);
}
void loop() {
  int x = analogRead(X_PIN);
  int y = analogRead(Y_PIN);
  Serial.printf("X=%d Y=%d SW=%s\n", x, y,
                digitalRead(SW_PIN) == LOW ? "pressed" : "released");
  delay(100);
}

Raw values demonstrate input changes, not calibrated voltage. Center need not be 2048, and 3.3 V can clip the classic ESP32 ADC measurement range. This monitor does not debounce SW; use the linked debouncing lesson before counting presses.

How it works

Technical references

• SparkFun Thumb Joystick hookup guide — Two potentiometers and push switch; module example, not proof of the pictured board.
• Espressif ADC API — Resolution, per-pin attenuation and classic ESP32 measurable range.
• Espressif GPIO API — INPUT_PULLUP and digitalRead.
• Espressif ESP32 ADC limitations — Classic ESP32 ADC2/Wi-Fi sharing restrictions.