esp32-core/libraries/Matter/examples/MatterDimmableLight

Matter Dimmable Light Example

This example demonstrates how to create a Matter-compatible dimmable 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.

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 a dimmable light device
• Support for both Wi-Fi and Thread(*) connectivity
• Brightness control (0-255 levels)
• 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 pins (or using built-in LED/RGB LED)
• User button for manual control (uses BOOT button by default)

Pin Configuration

• LED: Uses RGB_BUILTIN if defined, otherwise pin 2 (supports both RGB LED and regular LED with PWM brightness control)
• 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. 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 MatterDimmableLight.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 | brightness: 15
Matter Node is commissioned and connected to the network. Ready for use.
Light OnOff changed to ON
Light Brightness changed to 128

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)

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 a dimmable light in your Home app
7. You can control both the on/off state and brightness level (0-100%)

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 dimmable light will appear in your Alexa app
6. You can control brightness using voice commands like "Alexa, set light to 50 percent"

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 brightness using voice commands or the slider in the app

Code Structure

The MatterDimmableLight example consists of the following main components:

1. setup(): Initializes hardware (button, LED), configures Wi-Fi (if needed), sets up the Matter endpoint, restores the last known state (on/off and brightness) from Preferences, and registers callbacks for state changes.
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:
   • setLightState(): Controls the physical LED with brightness level (supports both RGB LED and regular LED with PWM).
   • onChangeOnOff(): Handles on/off state changes.
   • onChangeBrightness(): Handles brightness level changes (0-255).

Troubleshooting

• Device not visible during commissioning: Ensure Wi-Fi or Thread connectivity is properly configured
• LED not responding or brightness not working: Verify pin configurations and connections. For non-RGB LEDs, ensure the pin supports PWM (analogWrite)
• 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
• No serial output: Check baudrate (115200) and USB connection

Related Documentation

• Matter Overview
• Matter Endpoint Base Class
• Matter Dimmable Light Endpoint

License

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