SparkFun CO2 Humidity and Temperature Sensor - SCD40 (Qwiic)

This SparkFun CO₂ Humidity and Temperature Sensor features the next-generation SCD40 photoacoustic CO₂ sensor for high-accuracy environmental readings. The SCD40 utilizes Sensirion's PASens^® photoacoustic measurement system, which combines narrow-band IR light and a microphone inside the sensing package. This system is capable of detecting concentrations from 0 to 40,000 ppm with high accuracy over the range of 400-2000 ppm, with a precision of ±(50 ppm + 5%). The SCD40 features an integrated temperature and humidity CMOS sensor to enhance accuracy. For additional accuracy, the SCD40 also accepts ambient pressure readings! All this functionality comes in our standard 1in. x 1in. Qwiic form factor and will seamlessly integrate into your Qwiic-based projects. However, we still routed the I²C signals out to a set of 0.1in.-spaced pins for users who prefer a soldered connection.

The SCD40 features an automatic self-calibration routine that adjusts to its sensing environment over a seven-day calibration period. For best results, Sensirion recommends taking continuous readings for at least one hour a day of 'fresh air' for the calibration period to complete.

We've written an Arduino library to make reading the CO₂, humidity, and temperature very easy. It can be downloaded through the Arduino Library manager by searching for 'SparkFun SCD4x', or it can be found in the Documents tab above.

• Schematic
• Eagle Files
• Board Dimensions
• Hookup Guide
• Datasheet (SCD4X)
• Qwiic Information Page
• Libraries:
  • Arduino
  • Python / MicroPython / CircuitPython
• Github Hardware Repo