MQ131 ozone sensor power requirements and easyC pinout

TECHNICAL SUPPORT Sensors & Modules
1

Customer:

I recently purchased MQ131 ozone sensors with easyC connectors and am unable to get them to work properly. The documentation is confusing about the voltage requirements. Does the module require two power sources? 3V via easyC does not seem to heat up the sensor. I see notes in the datasheet indicating the sensor may also need 5V via the VCC breakout pin for the sensor heater. Can you clarify the wiring and power requirements, and explain the easyC pinout - which pins are for power, clock, and data?

Originally submitted via email support on 9 February 2026. Migrated to the forum for community visibility.

2

Soldered Support:

The Qwiic connector can provide enough power to the sensor. The sensor should be hot enough, especially after the 48h preheat time required. Connecting to the 5V and GND pins is only required if you are daisy-chaining multiple sensors on the same I2C bus (more than 2 from our tests), as there is a significant voltage drop which could cause the sensor not to work properly. Note that the MQ131 sensor is a High-concentration sensor, intended for ranges from 10 - 1000ppm.