Description

The M5Stack CO2 Unit is a compact digital air environment sensor for CO2 concentration, temperature, and humidity measurement. It integrates Sensirion’s SCD40 sensor, a power step-down circuit, and Grove I2C communication, making it easy to add indoor air-quality sensing to M5Stack controllers and automation projects.

This SCD40 CO2 sensor unit measures CO2 from 400 ppm to 2000 ppm with typical accuracy of (50 ppm + 5% of reading), while also reporting ambient temperature and relative humidity. With I2C address 0x62, HY2.0 4P connection, and a small enclosure with LEGO-compatible mounting holes, the I2C CO2 temperature humidity sensor is suited for ventilation checks, smart home dashboards, and classroom monitoring.

Features

• CO2 concentration detection: SCD40 sensor supports 400 ppm to 2000 ppm measurement range.
• Temperature and humidity measurement: monitors ambient temperature from -10 to 60 C and humidity from 0 to 95 %RH.
• I2C communication: uses Grove I2C at address 0x62 for simple host integration.
• Integrated power conversion: onboard 5V to 3.3V DC-DC circuit supports the sensor system.
• HY2.0 4P interface: connects directly to M5Stack controllers and Grove-compatible expansion ports.
• Mounting friendly: two LEGO-compatible holes simplify fixtures, enclosures, and teaching demos.

Specifications

Applications

• Indoor CO2 concentration detection
• Temperature and humidity monitoring
• Smart home air-quality dashboards
• Classroom, office, and workshop ventilation monitoring
• Environmental data logging with M5Stack controllers

Product List

Other Content

For stable readings, place the M5Stack CO2 Unit where air can circulate around the ventilation openings. Avoid sealing the enclosure, covering the sensing area, or mounting the unit directly beside heat sources that can distort temperature, humidity, or CO2 values.

The SCD40 CO2 sensor unit is useful when a project needs air-quality context together with temperature and humidity, such as checking whether a room needs ventilation or logging environmental trends over time.

Resources

• Product documentation
• Schematic PDF
• Schematic image
• Model size drawing
• SCD40 datasheet
• SY8089AAAC datasheet
• Arduino example for M5Atom
• Arduino example for M5Core
• Arduino example for M5Core2
• UIFlow1 documentation
• UIFlow2 documentation
• Home Assistant integration

FAQ

What does the M5Stack CO2 Unit measure?

It measures CO2 concentration, ambient temperature, and relative humidity through the SCD40 sensor.

What is the CO2 range?

The M5Stack CO2 Unit measures CO2 from 400 ppm to 2000 ppm.

What I2C address does it use?

The unit communicates through Grove I2C at address 0x62.