SONOFF Sensors

A while ago I posted about starting to use Home Assistant. This has been working well for monitoring our SolarEdge PV and Battery system, controlling if we should charge the battery with cheap overnight power if there has not been enough sun to fully charge the battery.

Bitten by the Home Assistant bug, I decided I wanted to add more sensors to the systems, so bought some cheap Zigbee equipment from AliExpress

The installation was easy using ZHA, the gateway dongle and sensors were all found. However, the sensor readings I got were strange. On startup a reading was received, this stayed as a flat line for 6 hours then nothing for 6 hours then a new, usually different, value for 6 hours, and on and on.

After looking at forums it seems that I am not alone in having this problem with SONOFF kit, and nothing seemed to fix the problem. The general consensus seemed to be to avoid the brand.

Well, yesterday they fixed themselves, or rather the sensors got a firmware update delivered automatially via ZHA from 0x00002100 to 0x00002200 that seems to have fixed the problem. As the chart at the top of this post shows I now have the type of data I was expecting.

So if you are seeing similar problems with SNZB-02P sensors, look out for a firmware update