M5Stack AtomS3 CO₂ Monitor with SCD41

An ESPHome-powered CO₂ monitoring device using M5Stack AtomS3 and SCD41 sensor, displaying real-time CO₂, temperature, and humidity data with visual feedback and native Home Assistant integration.

Features

• CO₂ value page with temperature and humidity display
• Smiley face page with CO₂ value display
• Green to red color transition and blinking alert for CO₂ level
• Kawaii face page for an intuitive CO₂ level impact indication
• Page navigation via under-display button click or in Home Assistant
• Home Assistant integration

Hardware Components

Component	Notes
M5Stack AtomS3	ESP32-based microcontroller with 0.85" screen
SCD41 CO2 Sensor	Sensirion CO2, temperature, and humidity sensor

Wiring

Standard cable shipped with the sensor should just work.

AtomS3 Pin	SCD41 Pin	Function
GPIO1 (TX)	SCL	I2C Clock
GPIO2 (RX)	SDA	I2C Data
5V	VDD	Power (5V)
GND	GND	Ground

Setup Instructions

1. Install ESPHome

python -m venv venv
source venv/bin/activate
pip install esphome

2. Create secrets file

Create a secrets.yaml file in the project directory with your WiFi credentials:

# secrets.yaml
wifi_ssid: "Your_WiFi_SSID"
wifi_password: "Your_WiFi_Password"

3. Build and upload

Connect the microcontroller to your computer via USB and run:

esphome run m5stack-atom-s3-co2l.yaml

License

This config is distributed under the MIT License.