SparkFun
SparkFun Air Quality Sensor - SGP40 (Qwiic)
The SparkFun SGP40 Air Quality Sensor measures volatile organic compound (VOC) levels in indoor environments using Sensirion's CMOSens technology. The metal ...
The SparkFun SGP40 Air Quality Sensor measures volatile organic compound (VOC) levels in indoor environments using Sensirion's CMOSens technology. The metal oxide (MOx) sensor with a temperature-controlled micro hotplate provides humidity-compensated air quality readings via I2C with Qwiic connectors for easy integration.
Rather than returning specific gas concentrations, the SGP40 outputs a digital value based on common indoor VOCs. Combined with Sensirion's VOC Index Algorithm, it detects the relative intensity of VOC events compared to average readings over a 24-hour period — think of it as an electronic nose for your room.
Key Features
- Sensirion SGP40 Sensor – MOx-based VOC detection with humidity compensation
- Qwiic / I2C Interface – Two Qwiic connectors for daisy-chaining; I2C address 0x59
- VOC Index Output – Processed output from 0–500 VOC Index points, plus raw signal (SRAW) 0–65535 ticks
- Fast Start-Up – Reliably detects VOC events in under 60 seconds; meets full specifications within 1 hour
- Low Power – 2.6 mA during continuous operation at 3.3 V; 34 μA idle with heater off
- Long-Term Stability – Robust against contaminating gases with low drift and minimal device-to-device variation
Specifications
- Operating Voltage – 1.7–3.6 V (typical 3.3 V via Qwiic)
- Current (Active) – 2.6 mA at 3.3 V
- Current (Idle) – 34 μA (heater off)
- I2C Address – 0x59
- Recommended Sampling Interval – 1 s (VOC Index); 0.5–10 s (SRAW)
Ideal For
- Indoor air quality monitoring
- Smart home and HVAC systems
- Environmental sensing projects
- Air purifier control and ventilation feedback
Package Contents
- 1× SparkFun SGP40 Air Quality Sensor (Qwiic)
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- CMOSens
- CMOSens is Sensirion’s integrated sensor technology that combines sensing elements and electronics in one package. It matters because it affects how the sensor measures temperature and humidity and how it is supported by the manufacturer’s libraries and datasheets.
- I2C
- I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.
- I2C address
- An I2C address is the number a device uses so a microcontroller can tell it apart from other devices on the same I2C bus. It matters because two devices with the same fixed address may conflict if used together.
- Qwiic
- Qwiic is a plug-in connector system for I2C devices that uses small 4-pin cables, so you can connect compatible sensors without soldering. It matters because your controller or adapter also needs Qwiic, or you will need a cable or breakout to wire it up.
- VOC
- Volatile organic compounds are gases released from things like paints, cleaners, smoke, and some plastics. A VOC reading helps indicate indoor air quality, but it is usually an index or estimate rather than a direct identification of each chemical.
Find this product in
Brands
SparkFun SGP40 Qwiic Schematic
Schematic · 128.2 KB · Click any page to view full size
Sensirion SGP40 Datasheet
Datasheet · 1.2 MB · Click any page to view full size
Sensirion VOC Index for Experts
Document · 1.4 MB · Click any page to view full size
Sensirion SGP40 Design-In Guide
User Guide · 304.4 KB · Click any page to view full size
SGP40 Quick Testing Guide
Quick Start · 507.9 KB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 701.1 KB · Click any page to view full size
Resources & Downloads
Guides, code examples, and more
Related Tutorials
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