This SparkFun CO2 Humidity and Temperature Sensor features the next-generation SCD41 photoacoustic CO2 sensor for high-accuracy environmental readings. The SCD41 uses Sensirion’s PASens photoacoustic measurement system that combines narrow-band IR light and a microphone inside the sensing package capable of detecting concentrations from 0 to 40000 ppm with high accuracy over 400-5000 ppm (40 ppm+5%).

The SCD41 has an integrated temperature and humidity CMos sensor to improve accuracy. For additional accuracy, the SCD41 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 SCD41 includes an automatic self-calibration routine to automatically adjust 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. This version of the SCD4X sensors also has a one-shot measurement option for an optimal reduction in power consumption.

We’ve written an Arduino library to make reading the CO, humidity, and temperature very easy. It can be downloaded through the Arduino Library manager: search for ‘SparkFun SCD4x’, or it can be found in the Documents tab below.

Get started with the Sparkfun SCD4X CO2 hookup guide

Features

• I2C Interface (Qwiic-enabled)
  • I2C Address: 0x62
  • 2x Qwiic Connectors
• Supply Voltage Range: 2.4-5.5V (3.3V Typ.)
• Low Current Consumption:
  • Normal Mode:
    • Max: [email protected]
    • Typ: [email protected]
  • Low Power Mode:
    • Typ: [email protected]
  • Single-Shot:
    • [email protected]
• Photoacoustic Measurement System
  • Sensirion’s PASens Technology
• Integrated Temperature and Humidity Sensor
  • Sensirion’s CMOSens Technology
• CO2 Output Range: 0-40,000ppm
• CO2 Measurement Accuracy: (40ppm + 5% of reading)
  • Conditions: 400-5,000ppm
• Humidity Range: 0-100%RH
• Humidity Accuracy: 9%RH (Full Range)
• Temperature Range: -10C-60C
• Temperature Accuracy: 1.5 (Full Range)

Resources

• Schematic
• Eagle Files
• Board Dimensions
• Hookup Guide
• Datasheet(SCD4X)
• Qwiic Information Page
• SCD4X Arduino Library
• Github Hardware Repo