CCS811 measures continuosly rising

[bigfoot996]

Hi guys,

first of all i want to give a big big thank you to the developer and everyone who is involved. I'm using Mycodo since a month to maintain healthy conditions in my grow box and I'm learning a lot of new things. I'm amazed by the tool and as soon as soon as i get my salary, my donation will go out! This has to be supported! =)

Describe the problem/bug

I am using a CCS811 (with temperature sensor) attached to a RPI5 running Mycodo.
The problem is: Once the sensor powers on, it starts at 400ppm by default, which should be also a valid measurement. Over the next few hours, the sensors measured value continuously and slowly rises until it somwhen stops at arround 1800ppm. If i restart it, same thing again -> starts at 400 and over the next, lets say 6 hours, it rises somewhere between 1500 and 1800 and stays there.
It's located in a big room where there is no people or other co2 sources anywhere near by - nothing. Windows are closed. There is big plants inside which should actually use co2, so the co2 level to be rising over hours without any reason is highly unlikely.

Versions:

• Mycodo Version: 8.5.13
• Raspberry Pi Version: [e.g. 3B+] Raspberry Pi 5 8 GB
• Raspbian OS Version: Debian 12 - 6.6.31+rpt-rpi2712

Reproducibility

Please list specific setup details that are involved and the steps to reproduce the behavior:

1. Activate the sensor (400ppm)
2. Wait and see how co2 value goes up to between 1500-1800 over a timespan of ~6h (stays in this range then)
3. deactivate the sensor
4. start over at 1.

Expected behavior

A relatively stable and valid measurement

Thanks and best greetings from Germany. Keep up the awesome work for this tool! <3

[kizniche]

I'm not sure why you're observing this, but there are no calculations being performed by Mycodo to calculate CO2 in this module. This would be a question for the developer of the CCS811 library the input module uses or the sensor manufacturer. Have you already read the datasheet?