Adafruit STCC4 + SHT41 CO2, Temperature & Humidity Sensor

Overview

Adafruit STCC4 and SHT41 CO2, Temperature & Humidity Sensor is a breakout board designed for indoor air monitoring. It combines the Sensirion STCC4 CO2 sensor with an onboard SHT41 temperature and humidity sensor, giving you a practical way to measure indoor carbon dioxide levels while also reading ambient temperature and relative humidity.

The STCC4 uses a thermal conductivity measurement principle rather than NDIR or photoacoustic sensing. For this design, the onboard SHT41 helps improve CO2 compensation, and because it is connected to the STCC4's secondary I2C port, your microcontroller only needs to communicate with the STCC4 to retrieve measurements.

This breakout includes the supporting circuitry needed for easy integration, along with SparkFun Qwiic compatible STEMMA QT connectors for solderless I2C wiring. It works with Arduino and CircuitPython/Python, making it suitable for microcontrollers as well as single-board computers such as Raspberry Pi.

Important: this sensor is tuned for indoor air measurement applications. It is not intended for scientific CO2 sensing or for environments where the gas composition is abnormal. Like other true CO2 sensors, it should be exposed to fresh outdoor air about once a week so it can self-calibrate to a 400 ppm baseline.

Specifications

Technical details for the STCC4 + SHT41 breakout board.

Pinout & Connections

The breakout is designed for straightforward I2C wiring through either the onboard STEMMA QT connectors or standard header pins.

What’s Included

• One fully assembled and tested PCB breakout
• One small piece of header

Notes

• QT cable is not included.
• If you want to use the included header, it must be soldered to the PCB.
• For breadboard use, header soldering is required.