SparkFun Air Quality Sensor - SGP40 (Qwiic)

The SparkFun SGP40 Air Quality Sensor is an innovative device designed to measure the quality of air in your indoor spaces. Utilizing Sensirion's CMOSens® technology, the SGP40 features a metal oxide (MOx) sensor with a temperature-controlled micro hotplate. This provides a humidity-compensated volatile organic compound (VOC) based indoor air quality signal. The sensor and VOC Algorithm are incredibly robust against contaminating gases found in real-world applications, ensuring long-term stability, low drift, and minimal device-to-device variation.

The SGP40 doesn't provide specific concentrations of VOC gases. Instead, it outputs a digital value reflecting the presence of common VOC gases in an indoor environment. This value can be used in conjunction with Sensirion's VOC Index Algorithm to detect the relative intensity of VOC events compared to the average readings over a 24-hour period. Essentially, the SGP40 is a highly sensitive electronic nose for VOC detection in your room.

Communication with the SGP40 is facilitated via I²C, and the sensor pins are broken out to Qwiic connectors. This allows easy integration with SparkFun's extensive Qwiic Ecosystem, which is a collection of I²C sensors, actuators, shields, and cables designed to make prototyping faster and less error-prone. The Qwiic system uses a common 1mm pitch, 4-pin JST connector to reduce the required PCB space, and its polarized connections ensure correct hook-up.

Features:

• I²C interface (Qwiic-enabled)
  • I²C Address: 0x59
  • 2x Qwiic connectors
• Operating voltage range:
  • 1.7V - 3.6V (Typically 3.3V)
  • The Qwiic interface provides 3.3V
• Typical current consumption:
  • 2.6mA during continuous operation (at 3.3V)
  • 34µA when idle (heater off)
• Output signal:
  • Digital raw value (SRAW): 0 - 65535 ticks
  • Digital processed value (VOC Index): 0 - 500 VOC Index points
• Switch-on behavior:
  • Time until reliably detecting VOC events: <60s
  • Time until specifications are met: <1h
• Recommended sampling interval:
  • VOC Index: 1s
  • SRAW: 0.5s - 10s (Typically 1s)

Documents:

• Schematic
• Eagle Files
• Board Dimensions
• Hookup Guide
• Sensirion SGP40 Datasheet
• Sensirion VOC Index for Experts
• Sensirion SGP40 Design In Guide
• SGP40 Quick Testing Guide
• Qwiic Information Page
• Arduino Library
• Python Package
• GitHub Hardware Repo