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CCS811 not useable

Posted: 19 Jul 2022, 09:51
by Rampler
Hi together,
a use the CJMCU CCS811 board with temperatur and humidity compensation via DHT22.
I am only interested in tVOC values.
The sensor had have enough time for burning, more than a week.
The sensor is installed in the toilet.
Unfortunately the ccs811 produces senseless peaks.
peaks.JPG
peaks.JPG (38.81 KiB) Viewed 3795 times
Any ideas ?

Now i am testing the sgp30 sensor, unitl now, no peaks :P

regards Klaus

Re: CCS811 not useable

Posted: 19 Jul 2022, 10:03
by Ath
Can that sensor be contaminated/schmutzig or just of poor quality? Especially as the SGP30 seems to be working as intended.

Re: CCS811 not useable

Posted: 19 Jul 2022, 10:11
by Rampler
Ath wrote: 19 Jul 2022, 10:03 Can that sensor be contaminated/schmutzig or just of poor quality? Especially as the SGP30 seems to be working as intended.
Good point.
i will order another CCS811 and test it again.

Re: CCS811 not useable

Posted: 19 Jul 2022, 10:20
by Ath
Or is someone visiting the toilet so these peaks are actually correct? :o :lol: :lol: :lol:

Re: CCS811 not useable

Posted: 19 Jul 2022, 13:16
by TD-er
Those VOC sensors are actually quite useless for measuring CO2.

Their behavior is changing really fast, so you cannot draw any conclusion based on their measurements.

Positioning them on the toilet may however be perfect for deciding when the fan should be turned on as one may produce quite potent "Volatile Organic Compound" gasses there.

Re: CCS811 not useable

Posted: 23 Jul 2022, 07:21
by Rampler
Now, i have tested with a new CCS811 sensor.
==> Same peaks

Nevertheless
I have seen that the peeks will caused from my DHT22 sensor.
I have choosen the "Enable temp/humid compensation:" in the CCS811 Plugin.
Therefore every time the DHT22 gets a "nan", TVOC and eCO2 will rise up.

The problem is caused from this:
https://github.com/letscontrolit/ESPEasy/issues/4026

regards Klaus

Re: CCS811 not useable

Posted: 23 Jul 2022, 10:57
by TD-er
OK, so this is for sure an issue with the CCS811 plugin, as it should not cause erratic behavior when fed with a NaN value.