adafruit / Adafruit_BME680

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Zero value on first read (gas) #43

Open factionone opened 3 years ago

factionone commented 3 years ago

Hi,

As subject, I'm finding that my first read of gas resistance from the sensor (with the performReading method) is always 0.00KOhms - is this expected behaviour?

Connecting with I2C. I'm using the latest library version; find the same result with the example sketch and in my own program. I have the earlier(?) version board without Qwiic/STEMMA QT connectors [but find the same using an el-cheapo module I bought from fleabay a while ago]. I've tried added various delays here in case the sensor needs more time to collect data before I read the value, but it makes no difference.

[Apologies for piggybacking issues, but] is there a recommended polling interval for accuracy on gas measurement, or perhaps a different heating temperature/duration I would use for polling once per minute? I find that with the example sketch (2s polling) gas resistance stabilises after some time at 55~60 KOhms, but in the same environment polling once per minute, it's significantly lower (<15 KOhms).

Thanks,

Rob.