SparkFun CO₂ Humidity and Temperature Sensor - SCD41 (Qwiic)

The SparkFun CO₂ Humidity and Temperature Sensor is a versatile, high-accuracy environmental sensor that uses the next-generation SCD41 photoacoustic CO₂ sensor. The SCD41 features Sensirion's PASens^® photoacoustic measurement system, which combines narrow-band IR light and a microphone to detect CO₂ concentrations from 0 to 40000 ppm with high accuracy over 400-5000 ppm ±(40 ppm+5%). The sensor also includes an integrated temperature and humidity CMos^® sensor for improved accuracy and accepts ambient pressure readings for additional precision. The sensor is housed in a standard 2.54cm x 2.54cm Qwiic form factor for easy integration into Qwiic-based projects, but also includes 2.54mm-spaced pins for users who prefer a soldered connection.

The SCD41 sensor includes 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. The SCD4X sensors also offer a one-shot measurement option for optimal reduction in power consumption.

SparkFun has developed an Arduino library to simplify reading the CO₂, humidity, and temperature data from the sensor. The library can be easily downloaded through the Arduino Library manager by searching for 'SparkFun SCD4x'.

The SparkFun Qwiic Connect System is an ecosystem of I²C sensors, actuators, shields, and cables designed to make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector, reducing the amount of required PCB space and ensuring polarized connections for error-free hook up.

The SparkFun SCD4x CO₂ sensor comes with a range of features including an I²C interface, a supply voltage range of 2.4-5.5V (3.3V typical), and low current consumption. It also includes Sensirion's PASens Technology and CMOSens Technology, a CO₂ output range of 0-40,000ppm, and a humidity range of 0-100%RH. The sensor operates within a temperature range of -10°C-60°C and offers temperature accuracy of ±1.5 (Full Range).

Additional resources including the schematic, Eagle Files, board dimensions, hookup guide, datasheet, and Arduino library can be found on the SparkFun website. These resources provide detailed information about the sensor and step-by-step instructions for using it in your projects.