SparkFun Nitrogen Dioxide Gas Sensor - GM-102B (Qwiic)

Product Overview

The SparkFun Qwiic Nitrogen Dioxide Gas Sensor is a compact and solderless solution for measuring nitrogen dioxide (NO₂) gas concentrations in indoor environments. Utilizing the Winsen GM-102B MEMS sensor, it detects NO₂ levels between 0.1 and 10 parts per million (ppm), routing the sensor's analog voltage fluctuations into an onboard 10-bit analog-to-digital converter (ADC) that delivers a clean digital signal directly over I²C.

Qualitative Measurement & Calibration

While the GM-102B measures nitrogen dioxide gas concentration, it returns only qualitative data; the data does not represent a specific concentration in ppm.

• Built-in ADC: The onboard 10-bit analog-to-digital converter takes the sensor's raw analog voltage output (with a sensitive material resistance of 1KΩ to 30KΩ) and feeds the converted data to your microcontroller over I²C (default address 0x50).
• Sensor Calibration: Because the baseline values are uncalibrated and can experience some crossover with other gases, you'll need to calibrate the output against known concentrations of NO₂ to extract useful ppm data.
• Operation Efficiency: Includes an onboard LDO power regulator configured to power the internal sensor heater with an 80Ω ±20Ω room-temperature resistance that consumes less than 40mW of power.

This breakout features a pair of Qwiic connectors for a completely solderless setup and works directly with the SparkFun GM-XX2B Arduino Library. For users who prefer a traditional breadboard circuit or need direct access to the analog signal, standard 0.1-inch-spaced plated through-hole (PTH) pins break out the 3.3V power, I²C lines, ADC Alert signal, and the sensor's raw V_OUT signal.v