Hi everyone - hopefully this is the right place to talk about this, but I recently built a “Sniffer” (this project) to test air quality and I’m running two BME680 plus PM 2.5 detectors on two ESP32 boards and am having a heck of a time trying to figure out why the readings on both BME680 are so consistently wacky.
Instead of using the standard BME680 integration, I’m using the one that includes the Bosch closed-source calculations - found here.
Problem is, I’m getting wild readings, as is a friend of mine with the same setup. I’ve got an Awair, so I have a good baseline of my house - usually hovering between 200-300 ppb VOC, but both of my BME680 report anywhere from 3000-9000 ppb VOC, sometimes spiking into the hundred-thousands which I know can’t be correct.
Related, they’re also pretty high in CO2 detection - where my Awair reports between 600-700 on average, my sniffers are both reading 1000-2000 - off, but not nearly as bad as the VOC readings.
I’ve got one on a windowsill with access to fresh air in hopes that maybe it’d “calibrate” over the course of a few days, but it’s been three weeks and both are still showing wild readings.
Barometer, thermometer, humidity, and the particulate sensor (a different device) are all working fine. Seems everything that is having an issue is related to the gas resistance sensor.
Does anyone have any idea what might be happening? Have I overlooked something? Thanks!