Deleting or smoothing data?

I have a DHT22 that gives about twice a day huge spurious values for humidity. I’ve replaced the sensor once already, and confirmed it has a resistor on it as recommended. Is there any way I can just “fix” this via smoothing or deletion of values outside a running windows of 1SD, etc, on the emoncms feed side? I have like 3 years of bad data now, I keep putting this off, and I want to fix it!


I see the same behavior with the DHT22 in my setup. I changed a couple of sensors, but the problem persists.
I see spikes in humidity - 3000 vs 55, and also in temperature - I got a minus 12 celsius instead of 25.
This happens once or twice a day.
To what piece of hardware is your DHT22 connected?

This may not be the automatic solution you’re looking for, but if you need to edit existing data manually, one data point at a time, check out Manually edit feed data (to delete bad data) - Is it possible? How?

For an automated filter for new incoming data, you could try using the “Max value allowed” process - it’s in the Inputs processes list. There are also some conditional processes in the list (such as “if >, skip next”) that you may be able to use to build a smoothing filter. Good luck!

1 Like

Looking at the Emoncms documentation, I found this useful script for our problem:

Sorry for the late reply. I’m using a RPi 3 to read the sensor. Never did get this figured out, TBH I kind of want to re-design the whole thing and use some more modern setup, but keep putting it off.