Gravity: I2C SCD41 Infrared CO2 Sensor (400 – 5000 ppm)

CO2 is a key factor for indoor air quality as high levels compromise the human cognitive performance and well-being.

This Gravity: SCD41 CO2 sensor is based on the SCD41 miniature CO2 sensor from Sensirion. SCD41 builds on the photoacoustic NDIR sensing principle and Sensirion’s patented PAsens® and CMOSens® technology to offer high accuracy at an unmatched price and the smallest form factor. On-chip signal compensation is realized with the built-in temperature and humidity sensor, while temperature and humidity data outputs are also available.

The SCD41 sensor detects the amount of energy that is absorbed by CO2 molecules. When pulsing the infrared emitter, CO2 molecules absorb infrared light periodically. This causes additional molecular vibration resulting in a pressure wave inside the measurement chamber. The higher the CO2 concentration, the more light is absorbed, and thus the greater the amplitude of this acoustic wave becomes. A microphone inside the gas chamber measures this, from which the CO2 concentration can then be calculated.

Learn more about PAsens® technology and NDIR sensors.

You can acquire the expansion shield shown in the diagram below, here.

Connection Diagram

Features

• CO2, temperature, and humidity, three in one
• Small size of 32*27*8mm
• Low power, average current＜4mA

Specifications

• Power Supply: 3.3V to 5V
• Average Operating Current: ＜4mA
• I2C Address: 0x62
• Product Size: 32*27*8mm/1.26×1.06×0.31′

CO2

• Accuracy: ±(40 ppm + 5% MV)
• Measuring Range: 400 – 5000 ppm
• Response Time: 60s

Humidity

• Typical Relative Humidity Accuracy: 6%RH
• Relative Humidity Measuring Range: 0 to 95%RH
• Response Time: 120s

Temperature

• Typical Temperature Accuracy: 0.8℃
• Temperature Measuring Range: -10 to 60℃
• Response Time: 120s

Pinout

Num	Label	Description
1	VCC	+
2	GND	–
3	SCL	I2C Clock Line
4	SDA	I2C Data Line

Package Contents

• 1x Gravity: SCD41 Infrared CO2 Sensor
• 1x Gravity-4P I2C/UART Sensor Cable