SDS011 Fan run's 24/7


I noticed that the SDS011 fan never stops anymore.
I thought initially it was running every 5 min. for a measurement.
300 sec. interval is configured



Why did you change for 300 s.? Are you sure you have not configure 3 s.?

The symptom you describe happens when the sensors is not connected with the WiFi anymore. Can you still see it on the map ? Can you still access to the sensor through the router ? Or can you see the Network AirRohr-XXXXX when you restart the sensor ?

Please send me the IDs. I will check here:
and here:

ID: 4390992 (807d3a430050)
Firmware-versie: NRZ-2020-133/NL (Nov 29 2020)
300 sec (= every 5 min) is sufficient for the web display

The graphs look normal.
Are you sure the fan is turning constantly ?

Yes it is running 24/7

Can I have some screenshots of the configuration interface There is no function in the firmware to keep the fan running between the measurements.

This can also happen when the wiring isn’t correct, especially the ground wire. I would check all the wires.
Before you do that, silly question obviously, but did you try turning it off and back on again? XD

Initially it was working correct, for years!

I disconnected the SDS011 and tested it with a USB <> Serial adapter with the testing software from the Nova site

SDS011 Laser Dust Sensor testing software\Nova PM2.5 Sensor Software-En-V1.88\Laser PM25 Sensor V1.88
Run as Administrator > SPM25Data.exe (otherwise COM port is not found)

That was all correct.

So the NodeMCU v3 was the culprit.
I erased the NodeMCU and flashed the latest.bin again.
The fan was still running 24/7

I replaced the NodeMCU v3 and now everything is OK.

Thanks for your help.

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