Help diagnosing z-wave issue

My z-wave network had been stable and operating well for almost 2 years with about a dozen nodes. I’m running Hassio on a Raspberry Pi 3 with the UZB stick.

Around the time when I upgraded HA from 0.81 to 0.83 I started getting issues where my zwave devices stop responding after several hours (8-48 hrs from the logs I’ve kept). In looking at the OZW_Log, it seems that all of the nodes, including node001 (the controller) stop responding.

‘Heal Network’ doesn’t restore the network
Restarting Homeassistant doesn’t restore the network
Hassio host reboot DOES restore the network
Power cycling the Pi DOES restore the network

I have since updated to HA 0.85, then 0.86.1 and now 0.86.2, and still have the same issue.

At this point, mt best guess is that my UZB stick has gotten flaky.

Also, I’m not sure, but my power supply might be making a louder hum than it did before so that might be a cause. I hooked it up to my oscilloscope and the output looked pretty stable, but trying to catch a glitch that happens once every 8-48 hrs is sort of challenging.

I know there were some changes to OZW that were done in 0.82, so I can’t rule out a software issue. Is there an easy way to do a downgrade in Hassio? I tried the method I found here:


curl -d ‘{“version”: “0.81.6”}’ http://hassio/homeassistant/update

to get the last known good version, and hassio responded with

401: Unauthorized

Well I think I have solved it.

It seems it was a power quality issue after all.

I have 12v going to my (former) alarm panel, which is where the Raspberry Pi is located. That 12v powers the hardwired motion sensors and glass break sensors which I am reusing. So, to generate the 5v power for the Pi, I am using one of these cheap converters:

This worked just fine for two years, but now either the 12v supply or the UBEC must be generating some glitches. I added a 220µF capacitor across the input to the UBEC and another across the output (belt and suspenders) to smooth out the power, and things are back to working great again.

In order to add the capacitors I made a couple of little pigtails that I inserted in-line with the UBEC. But afterward, I started to wonder if it wouldn’t have just been simpler to make a little jumper with a capacitor that I could connect to a pair of 5v power & ground pins on the Raspberry Pi GPIO. The Pi already has a 220µF capacitor on board for the 5v rail, but maybe that’s not enough to clean up the power for the UZB stick in my case.

Anyway, thought I’d mention this in case others have similar issues.