Temp & Hum Steeply Decline for Seconds After Power Up the Open Air (O-1PST)

[Tai_D]

Hi! I roughly mentioned this issue with Nick this morning, but I didn’t provide a detailed description of the issue. So I’m here to give some more.

In this case, I log the data to my Home Assistant from the Open Air (O-1PST).

I found that every time the Open Air (O-1PST) is powered up, at its first 3-10 seconds, it reports severely declined temperature and humidity readings (temperature is more obvious to notice the false data).

This issue doesn’t seem to be a problem for AirGradient Dashboard as it may not report the readings as frequently as to my Home Assistant.

So I think, maybe, is it possible to have a setting that waits for the sensor to stabilize after the power up before starting to report readings?

Please let me know if you need more details, like a full CSV log.

Thanks!

[MallocArray]

I haven’t reviewed the code, but I wonder if HA is getting a short term average of temperature, and if during a reboot it sometimes gets 0 or NaN that throws off the average during the first boot.

You could connect the USB cable to your computer and watch the logs with the same page used to flash the firmware so you can see all of the logs in realtime and cause a reboot of the device and watch what kind of values it is showing

[nickf1227]

This is most certainly the issue and is probably expected behavior. How often are you rebooting your unit?