In this user-generated project, developer Mike Rankin showcases a compact CO₂ monitor built around the Sensirion STCC4 sensor and an ESP32-C6. Designed as a successor to earlier SCD40-based implementations, the project highlights how the ultra-small STCC4 enables accurate CO₂ sensing in space-constrained designs while extending the measurement range up to 5000 ppm.
The custom board integrates USB-C power, a display, and a Qwiic I²C connector for additional sensors, with the STCC4 working in combination with a closely coupled SHT40 for temperature and humidity compensation. This project provides practical insight into mechanical design trade-offs, thermal considerations, and component selection when building compact air quality devices with Sensirion sensors.
View the full project details, hardware design, and source files on GitHub.
Find out more about the STCC4 CO₂ sensor in our catalog.