ESP32 S3 - Button - Debounce
Mechanical buttons are deceptively simple components, but they come with a quirk that can trip up your ESP32 S3 projects: chattering. This tutorial walks you through what chattering is, why it matters, and how to eliminate it using both raw Arduino code and the ezButton library.
What you'll build:
- A test sketch that demonstrates button chattering without debounce
- A debounced button sketch using manual timing with millis()
- A single-button debounce example using the ezButton library
- A multi-button debounce example handling three buttons simultaneously
When you press a button, does its state change from LOW to HIGH (or HIGH to LOW) just once? Not quite! In the real world, a single button press causes the state to toggle between LOW and HIGH multiple times very quickly. This is a physical characteristic of mechanical buttons called chattering. The chattering phenomenon makes your ESP32 S3 read multiple button presses when you only pressed it once, causing errors in your projects. The solution to eliminate this issue is called button debounce.
This tutorial covers:
- Debouncing a single button with built-in ESP32 S3 code
- Using the ezButton library for simple debounce implementation
- Handling multiple buttons with debounce on ESP32 S3
- Comparing results with and without debounce
Hardware Preparation
Or you can buy the following kits:
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Additionally, some of these links are for products from our own brand, DIYables .
Wiring Diagram
Connect a single button to your ESP32 S3 by wiring one pin to GPIO7 and the other pin to GND. The ESP32 S3's internal pull-up resistor handles the rest, so no external resistor is required.
This image is created using Fritzing. Click to enlarge image
Safety Notes
Always connect the button between a GPIO pin and GND rather than directly to 3.3V, since the code relies on the internal pull-up configuration. Avoid connecting buttons to GPIO0 during development, as it is used by the bootloader on the ESP32 S3.
| Button Pin | ESP32 S3 Pin |
|---|---|
| One pin | GPIO7 |
| Other pin | GND |
To see the difference clearly, we'll run ESP32 S3 code WITHOUT debounce first, then WITH debounce, and compare the results.
Reading Button without Debounce
Detailed Instructions
- New to ESP32 S3? Complete our Getting Started with ESP32 S3 guide first.
- Wire the components: Follow the wiring diagram shown above to connect the button to pin GPIO7.
- Connect the board: Plug your ESP32 S3 into your computer using a USB Type-C cable.
- Open Arduino IDE: Launch the Arduino IDE on your computer.
- Select your board: Choose "ESP32S3 Dev Module" and the correct COM port from the Tools menu.
- Upload the code: Copy the code below and upload it to your ESP32 S3 board.
- Open Serial Monitor: Click the Serial Monitor icon to view the output.
- Test the button: Press the button once and hold it for several seconds, then release it.
- Observe the results: Watch the Serial Monitor output showing multiple press/release events.
- Pro Tip: If you don't see chattering immediately, try pressing the button several times — it's a random phenomenon that appears intermittently.
Serial Monitor Output:
⇒ As you can see, you pressed the button only once and released it once, but the ESP32 S3 detected multiple presses and releases due to chattering.
※ NOTE THAT:
The chattering phenomenon does not happen all the time. If it does not happen, please try the above test several times to observe it.
We Made It Simple - ESP32 S3 Button Debounce Code with Library
We created the ezButton library to make button debouncing much easier, especially when working with multiple buttons on your ESP32 S3. Instead of managing timing variables manually, the library handles all debounce logic internally, giving you clean and readable code regardless of how many buttons you are managing.
Learn more: ezButton library documentation
ESP32 S3 Button Debounce Code for A Single Button
The following sketch shows how to debounce a single button using the ezButton library on ESP32 S3. After including the library and setting the debounce time, detecting a press or release is as simple as calling isPressed() or isReleased() inside the main loop.
ESP32 S3 Button Debounce Code for Multiple Buttons
This sketch demonstrates how to debounce three buttons simultaneously on your ESP32 S3 using the ezButton library. Each button gets its own ezButton object, and calling .loop() on all three inside the main loop keeps every button's debounce state up to date independently.
The wiring diagram
Connect three buttons to your ESP32 S3 as shown below.
This image is created using Fritzing. Click to enlarge image
| Button | ESP32 S3 Pin |
|---|---|
| Button 1 | D5 and GND |
| Button 2 | D6 and GND |
| Button 3 | D7 and GND |
Serial Monitor Output:
Application Ideas
Button debounce is a foundational technique that unlocks reliable input handling across a wide range of ESP32 S3 projects. Here are some practical applications where accurate button press detection is essential:
- Door lock systems: Keypad entry systems where each button press must register exactly once.
- Game controllers: Responsive button input for DIY gaming peripherals built on the ESP32 S3.
- Home automation remotes: Reliable control of lights, fans, or appliances from custom remote panels.
- Menu navigation: Multi-button navigation for OLED or TFT display menus on ESP32 S3 devices.
- Event counters: Counting circuits that increment precisely once per physical press.
- Security keypads: Alarm or access control systems requiring dependable input detection.
Video Tutorial
Watch the step-by-step video walkthrough for this ESP32 S3 project below.
Challenge Yourself
Practicing debounce with progressively complex scenarios is the best way to build confidence with ESP32 S3 input handling. Try these challenges to deepen your understanding:
- Beginner: Change the DEBOUNCE_TIME value to 20ms, 50ms, and 100ms and observe how each value affects button response on your ESP32 S3.
- Intermediate: Add an LED that toggles on and off with each debounced button press, demonstrating clean state management.
- Intermediate: Build a press counter that increments only once per button press and displays the running total on the Serial Monitor.
- Advanced: Implement a 4-button menu system where each debounced button performs a distinct action on the ESP32 S3.
- Advanced: Add long-press detection so a short press and a hold trigger different behaviors using a single button.
Additional Knowledge
Important debounce tips for ESP32 S3:
- The DEBOUNCE_TIME value depends on your specific button hardware
- Different buttons may require different debounce times (typically 20-100ms)
- Start with 50ms and adjust if you still see chattering
- Debounce techniques also work for switches, limit switches, reed switches, and touch sensors
- Hardware debounce (using capacitors) can complement software debounce for critical applications