esp32-core/libraries/Matter/examples/MatterOnOffLight

Matter On/Off Light Example

This example demonstrates how to create a Matter-compatible on/off light device using an ESP32 SoC microcontroller.
The application showcases Matter commissioning, device control via smart home ecosystems, and manual control using a physical button with state persistence.

Supported Targets

SoC	Wi-Fi	Thread	BLE Commissioning	LED	Status
ESP32	✅	❌	❌	Required	Fully supported
ESP32-S2	✅	❌	❌	Required	Fully supported
ESP32-S3	✅	❌	✅	Required	Fully supported
ESP32-C3	✅	❌	✅	Required	Fully supported
ESP32-C5	❌	✅	✅	Required	Supported (Thread only)
ESP32-C6	✅	❌	✅	Required	Fully supported
ESP32-H2	❌	✅	✅	Required	Supported (Thread only)

Note on Commissioning:

• ESP32 & ESP32-S2 do not support commissioning over Bluetooth LE. For these chips, you must provide Wi-Fi credentials directly in the sketch code so they can connect to your network manually.
• ESP32-C6 Although it has Thread support, the ESP32 Arduino Matter Library has been pre compiled using Wi-Fi only. In order to configure it for Thread-only operation it is necessary to build the project using Arduino as an IDF Component and to disable the Matter Wi-Fi station feature.
• ESP32-C5 Although it has Wi-Fi 2.4 GHz and 5 GHz support, the ESP32 Arduino Matter Library has been pre compiled using Thread only. In order to configure it for Wi-Fi operation it is necessary to build the project using Arduino as an ESP-IDF component and disable Thread network, keeping only Wi-Fi station.

Features

• Matter protocol implementation for an on/off light device
• Support for both Wi-Fi and Thread(*) connectivity
• Simple on/off control
• State persistence using Preferences library
• Button control for toggling light and factory reset
• Matter commissioning via QR code or manual pairing code
• Integration with Apple HomeKit, Amazon Alexa, and Google Home (*) It is necessary to compile the project using Arduino as IDF Component.

Hardware Requirements

• ESP32 compatible development board (see supported targets table)
• LED connected to GPIO pin (or using built-in LED) for visual feedback
• User button for manual control (uses BOOT button by default)

Pin Configuration

• LED: Uses LED_BUILTIN if defined, otherwise pin 2
• Button: Uses BOOT_PIN by default

Software Setup

Prerequisites

1. Install the Arduino IDE (2.0 or newer recommended)
2. Install ESP32 Arduino Core with Matter support
3. ESP32 Arduino libraries:
   • Matter
   • Preferences
   • Wi-Fi (only for ESP32 and ESP32-S2)

Configuration

Before uploading the sketch, configure the following:

1. Wi-Fi credentials (if not using BLE commissioning - mandatory for ESP32 | ESP32-S2):

   const char *ssid = "your-ssid";         // Change to your Wi-Fi SSID
   const char *password = "your-password"; // Change to your Wi-Fi password
   

2. LED pin configuration (if not using built-in LED):

   const uint8_t ledPin = 2;  // Set your LED pin here
   

3. Button pin configuration (optional): By default, the BOOT button (GPIO 0) is used for the Light On/Off manual control and factory reset. You can change this to a different pin if needed.

   const uint8_t buttonPin = BOOT_PIN;  // Set your button pin here
   

Building and Flashing

1. Open the MatterOnOffLight.ino sketch in the Arduino IDE.
2. Select your ESP32 board from the Tools > Board menu.

3. Select "Huge APP (3MB No OTA/1MB SPIFFS)" from Tools > Partition Scheme menu.

4. Enable "Erase All Flash Before Sketch Upload" option from Tools menu.
5. Connect your ESP32 board to your computer via USB.
6. Click the Upload button to compile and flash the sketch.

Expected Output

Once the sketch is running, open the Serial Monitor at a baud rate of 115200. The Wi-Fi connection messages will be displayed only for ESP32 and ESP32-S2. Other targets will use Matter CHIPoBLE to automatically setup the IP Network. You should see output similar to the following, which provides the necessary information for commissioning:

Connecting to your-wifi-ssid
.......
Wi-Fi connected
IP address: 192.168.1.100

Matter Node is not commissioned yet.
Initiate the device discovery in your Matter environment.
Commission it to your Matter hub with the manual pairing code or QR code
Manual pairing code: 34970112332
QR code URL: https://project-chip.github.io/connectedhomeip/qrcode.html?data=MT%3A6FCJ142C00KA0648G00
Matter Node not commissioned yet. Waiting for commissioning.
Matter Node not commissioned yet. Waiting for commissioning.
...
Initial state: ON
Matter Node is commissioned and connected to the network. Ready for use.
User Callback :: New Light State = ON
User Callback :: New Light State = OFF
User button released. Toggling Light!
User Callback :: New Light State = ON

Using the Device

Manual Control

The user button (BOOT button by default) provides manual control:

• Short press of the button: Toggle light on/off
• Long press (>5 seconds): Factory reset the device (decommission)

State Persistence

The device saves the last known on/off state using the Preferences library. After a power cycle or restart:

• The device will restore to the last saved state (ON or OFF)
• The Matter controller will be notified of the restored state
• The LED will reflect the restored state

Smart Home Integration

Use a Matter-compatible hub (like an Apple HomePod, Google Nest Hub, or Amazon Echo) to commission the device.

Apple Home

1. Open the Home app on your iOS device
2. Tap the "+" button > Add Accessory
3. Scan the QR code displayed in the Serial Monitor, or
4. Tap "I Don't Have a Code or Cannot Scan" and enter the manual pairing code
5. Follow the prompts to complete setup
6. The device will appear as an on/off light in your Home app

Amazon Alexa

1. Open the Alexa app
2. Tap More > Add Device > Matter
3. Select "Scan QR code" or "Enter code manually"
4. Complete the setup process
5. The light will appear in your Alexa app
6. You can control it using voice commands like "Alexa, turn on the light" or "Alexa, turn off the light"

Google Home

1. Open the Google Home app
2. Tap "+" > Set up device > New device
3. Choose "Matter device"
4. Scan the QR code or enter the manual pairing code
5. Follow the prompts to complete setup
6. You can control it using voice commands or the app controls

Code Structure

The MatterOnOffLight example consists of the following main components:

1. setup(): Initializes hardware (button, LED), configures Wi-Fi (if needed), initializes Preferences library, sets up the Matter endpoint with the last saved state (defaults to ON if not previously saved), registers the callback function, and starts the Matter stack.

2. loop(): Checks the Matter commissioning state, handles button input for toggling the light and factory reset, and allows the Matter stack to process events.

3. Callbacks:

   • setLightOnOff(): Controls the physical LED based on the on/off state, saves the state to Preferences for persistence, and prints the state change to Serial Monitor.

Troubleshooting

• Device not visible during commissioning: Ensure Wi-Fi or Thread connectivity is properly configured
• LED not responding: Verify pin configurations and connections
• State not persisting: Check that the Preferences library is properly initialized and that flash memory is not corrupted
• Failed to commission: Try factory resetting the device by long-pressing the button. Other option would be to erase the SoC Flash Memory by using Arduino IDE Menu -> Tools -> Erase All Flash Before Sketch Upload: "Enabled" or directly with esptool.py --port <PORT> erase_flash
• Button not toggling light: Ensure the button is properly connected and the debounce time is appropriate. Check Serial Monitor for "User button released" messages
• No serial output: Check baudrate (115200) and USB connection

Related Documentation

• Matter Overview
• Matter Endpoint Base Class
• Matter On/Off Light Endpoint

License

This example is licensed under the Apache License, Version 2.0.