Great, thank you both!
Ath wrote: ↑13 Jan 2024, 10:46
localhorst wrote: ↑13 Jan 2024, 02:01
But I've left this settings untouched / default (400000/100000):
The default values should not need adjusting for this sensor, and it is already set to "Force Slow I2C speed" by default, as the SDC30 specs say it only supports up to 100 kHz.
Fine - and yes, the SCD30 is doing its job reliable and without any problems so far.
TD-er wrote: ↑13 Jan 2024, 11:03
As Ton said, you shouldn't need to set the "normal" clock speed for I2C.
However if there are other devices connected to the same I2C bus and this SCD30 is really not tolerant to high clock frequencies, then you might need to lower the normal clock speed too.
Currently, there is the SSD1306 display on the same I2C bus - but doesn't seem to bother.
For the moment I've disconnected the BMP280 and SHT21 - who would also run on the same I2C bus. I need to solder the cables for connection.
Do you think connecting the both will cause trouble with the current settings and the SCD30?
TD-er wrote: ↑13 Jan 2024, 11:03
But if that's really an issue, you might want to consider using an I2C port expander as this also can isolate clocks not intended for a specific port.
Those I2C port expanders are really versatile as they can be used as level converters to isolate 5V devices in a separate bus and allow for longer cables to a specific device (and thus need special settings like lower clock speed, maybe stronger pull-up resistors, etc)
Thank you very much - but I'd rather leave the BMP280 and SHT21 out of the assembly than doing this big effort.
In my use case it's nice to have more or less precise temperature, humidity and air pressure - but this is second. I really need the precise CO2 measurement for my automation - and it should just reliably do.
For temperature etc, there are more than enough sensors in our apartment and temperature / radiators are controlled very well and with other sensors.
Anyways, I'll solder the needed cables to connect and try out the BMP280 and SHT21 together with the display and the SCD30.
When all the testing is done, I'll modify 3 more measuring stations with the SCD30 / exchanging the Senseair S8.
Have a nice weekend!
Kevin