ESP32 Matter Temperature and Illumination Sensor

Introduction

This code demonstrates a proof of concept for an IoT sensor setup to measure temperature, humidity, illumination (lux), and even co2, using the Matter standard.

Required Hardware

• Adafruit ESP32 Feather microcontroller
• BMP280 Temperature and Pressure Sensor (connected using the I2C protocol)
• BH1750 Light Sensor (connected using the I2C protocol)
• Matter hub (Apple TV 4k 3rd Gen with Ethernet)
• iPhone with the Apple Home App installed

Resources

• ESP-IDF: Espressif's official IoT Development Framework

• Documentation for setting up Matter

• Matter Building and Comissioning Guide

• ESP-MATTER: Espressif's official SDK for Matter applications

  • Link to a forked repository which includes functions for light and pressure readings

• ESP-IDF-LIB: Library containing drivers for sensor readings

Purpose

The purpose of this code is to provide a sample implementation of a temperature and illumination IoT sensor setup using the Matter standard. The code can be used as a starting point for building similar IoT sensor applications.

Setup Procedure (Apple Silicon Mac)

This setup procedure was test with an Apple Silicon Mac, but could likely be modified to work for Intel Macs, Linux machines, and potentially Windows.

Step 1: Clone repository

  git clone --recursive https://github.com/samuel-barrett/esp32-matter-sensor-test.git

Step 2: Get ESP-Matter Fork

• Install git lf

  brew install git-lfs 
  

• Clone the repository, using the following command:

  git clone --recursive https://github.com/samuel-barrett/esp-matter.git
  

• If you have cloned the repository, but need to add the submodules, use:

  git submodule update --init --recursive
  

• If you alerady have ESP-MATTER installed, you can do a shallow clone, and then fork that repository to use the samuel-barrett/esp-matter.git remote fork

  • To preserve your current esp-matter repository, you can copy the contents first

    cp -rH [PATH TO ESP-MATTER]/esp-matter [SOME PATH]/esp-matter-fork
    

  • Then change directories to the esp-matter repository you want to modify, and change the remote to point to this fork: samuel-barrett/esp-matter

    cd [ESP-MATTER Repository to modify]
    git remote set-url origin https://github.com/samuel-barrett/esp-matter.git
    git pull
    

• Enable IDF_CCACHE

  echo "export IDF_CCACHE_ENABLE=1" >> ~/.zshrc
  source ~/.zshrc
  

Step 3: Install and Configure the ESP-IDF and VSCode Extension

• Install prerequisites:

  # Install prerequisites
  brew install cmake cmake-docs ninja dfu-util ccache
  xcode-select --install
  
  # Clone version 4.4.3 of the ESP-IDF repo
  git clone --recursive https://github.com/espressif/esp-idf.git
  cd esp-idf
  git checkout v4.4.3
  git submodule update --init --recursive
  
  source ~/.zshrc
  source ~/.zprofile
  
  # Install esp32
  cd ~/esp-idf
  ./install.sh esp32
  . ./export.sh
  

• Install Visual Studio Code if not installed

• Install and configure the extension named "Espressif IDF" by following the instructions provided here

  • Note: If you have done a recursive clone then, the esp-idf repository is already downloaded, and you can select it during setup at esp32-matter-sensor-test/esp-idf

Step 4: Setup Matter

• Install Prerequisite software (See: here)

  brew install openssl pkg-config
  
  echo 'export PATH="/opt/homebrew/opt/openssl@3/bin:$PATH"' >> ~/.zshrc
  echo "export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:\"/opt/homebrew/opt/openssl@3/lib/pkgconfig\"" >> ~/.zshrc
  
  echo "export LDFLAGS=\"-L/opt/homebrew/opt/openssl@3/lib\"" >> ~/.zshrc
  echo "export CPPFLAGS=\"-I/opt/homebrew/opt/openssl@3/include\"" >> ~/.zshrc
  

• You may need to install ZAP

• Activate

  cd esp-matter/connectedhomeip/connectedhomeip/
  source scripts/activate.sh
  

Step 5:

• CD to esp32-matter-sensor-test

  cd [PATH]/esp32-matter-sensor-test
  

• Set ESP_MATTER_PATH

  export ESP_MATTER_PATH="[# PATH to esp matter (e.g. /Users/esp-user/esp-matter)]"
  

• Set target

  idf.py set-target esp32
  

• Add mdns dependency

  idf.py add-dependency "espressif/mdns^1.0.7"
  

• Make sure you are using a python version from .espressif

  which python
  or
  which python3
  

• Install lark

  python -m pip install lark stringcase
  or
  python3 -m pip install lark stringcase
  

• Open the esp32-matter-sensor-test folder in visual studio code

• Type [CMD]+[SHIFT]+[P], then type

  >ESP-IDF: Install ESP-Matter
  

• Select "Yes, download all submodules" -> "Use existing repository"

  • Select the forked repository from the previous step

• Select the port to use

  >ESP-IDF: Select port to use (COM,tty, usbserial)
  

• Type [CMD]+[SHIFT]+[P], then type

  >ESP-IDF: Build your project
  

Step 5: Configure hardware

• Connect the BMP280, and BH1750 sensors to the microcontroller using the i2C protocol

• To ensure, that the devices are connected properly, you can use the Arduino I2C scanner sketch

  • First install the Arduino ID ESP32 addon

Step 6: Build flash and monitor

• Select the correct Serial port and flash method (tested using UART), and then

• Build and flash the code to the ESP32 microcontroller using the ESP-IDF tools. Type [CMD]+[SHIFT]+[P], then

  >ESP-IDF: Build, Flash and start a monitor on your device
  

Step 7: Connect device via QR code

TODO: Find out how to get QR code

Limitations

The code has been tested with a very specific set of devices, and is not designed to be portable. It can however, be modified to fit

Future Work

The code is currently a basic implementation of the temperature and illumination sensor setup, and there is potential for future updates and improvements, such as:

• Adding more sensors or endpoints
• Adding support for different kinds of ESP32 development boards
• Improving the logging and data storage functionality
• Adding support for remote management and control

Conclusion