search

bryn51 / smartcitizen-kit-21-WIP

Work-in-Progress to add sensors and I2C Mux
GNU General Public License v3.0
2 stars 0 forks source link

SCD41 CO2 sensor delivers zero values for reading #3

Closed bryn51 closed 2 years ago

bryn51 commented 2 years ago

The SCD41 sensor is delivering values of 0 ppm for CO2; whilst Temperature and Humidity readings appear normal for this device (albeit different than readings from Urban board sensors).

This is likely to be an issue with the way the board is being driven; not the device itself.

bryn51 commented 2 years ago

This issue has been partly solved. Removal of Pressure Compensation call during SCD4x::start() is what fixed it. However now the Co2 concentration reading is a ridiculous value (i.r.o. 17000 ppm).

I may need to reach out to sensiron support to help fix this; I am have tried using information from documentation to no avail up to this point.

I might try connecting the device to an Arduino and running it independently of SCS V3 using example code and see what results I get.

bryn51 commented 2 years ago

I purchased another SCD41 Device from a different vendor (Adafruit); with similar results.

bryn51 commented 2 years ago

This (zero readings) is no longer the problem.

We now get readings; they are just a lot higher than expected; IRO 1500 ppm instead of more likely 420-480 ppm

I will close this issue but keep an eye on it. I am hoping that the Forced Recalibrations and Auto Recalibration mechanisms will fix the problem over time.