Product description
Sensor module from Adafruit for measuring carbon dioxide (CO2) concentration, temperature, and relative humidity. The module combines Sensirion's STCC4 CO2 sensor with the SHT41 temperature and humidity sensor. Suitable for monitoring indoor climate, ventilation systems, and other applications where air quality needs to be monitored.
Unlike simpler air quality sensors that estimate CO2 concentration based on the concentration of volatile organic compounds (VOCs), the STCC4 measures the actual carbon dioxide concentration. The sensor uses a measurement principle based on the thermal conductivity (TC) of gases, enabling a very compact design and low power consumption.
The STCC4 measures carbon dioxide concentration by heating the air in a small measurement chamber and monitoring heat transfer. The measurement principle is specifically designed for normal indoor air and is suitable for applications such as ventilation monitoring in homes, offices, and classrooms.
The integrated SHT41 sensor measures temperature and relative humidity with high accuracy. These measurements are also used to improve CO2 measurement accuracy. The SHT41 is connected to the STCC4's secondary I2C interface, meaning that all measurements can be retrieved through communication with the STCC4. This means that only one software library is required.
The module communicates via I2C and features two Qwiic connectors, making it easy to connect to Arduino, ESP32, and Raspberry Pi without soldering. A pin header is also included and can be soldered onto the board for connection to a breadboard.
Adafruit provides ready-to-use software libraries for Arduino and CircuitPython/Python, simplifying integration into custom projects.
Specifications:
- Manufacturer: Adafruit
- Product number: 6478
- CO2 sensor: Sensirion STCC4
- Temperature and humidity sensor: Sensirion SHT41
- CO2 measurement principle: Thermal conductivity (TC)
- CO2 accuracy: ±(100 ppm + 10%) at 400–5000 ppm
- Temperature accuracy: ±0.2 °C (typical, 0 to 75 °C)
- Humidity accuracy: ±1.8% RH (typical, 25 to 75% RH)
- Temperature measurement range (SHT41): -40 to +125 °C
- Humidity measurement range (SHT41): 0–100% RH
- Supply voltage: 3.3–5 V
- Interface: I2C
- STCC4 I2C address: 0x64 (default), alternatively 0x65
- SHT41 I2C address: 0x44 (via the STCC4's secondary I2C interface)
- STCC4 current consumption: Below 100 µA (average during occasional measurements)
- SHT41 current consumption: 0.4 µA (typical at 1 measurement/s, sensor only)
- Connection: 2x Qwiic and solderable pin header
- Supplied with: Pin header (not pre-soldered)