My Z-stick USB address changes

I hope this is the right place to ask. I’m new here and new to Home Assistant and to Z-Wave, but I have a few years experience with Raspberry Pi.

I installed Home Assistant 0.72.1 on a Pi 3B, added a Aeotec Z-Stick Gen5.

To add Z-Wave, I first looked for the Z-Stick address with ls /dev/ttyACM* and found it as ttyACM0. Fine, I added this to my configuration.yaml file:

zwave:
usb_path: /dev/ttyACM0

I restarted home-assistant.service and the Z-Stick showed up as expected.

Next, I unplugged the Z-stick to pair it with an Inovelli Z-wave switch. Then I plugged it back into the Pi. Now when I go to the Home Assistant Overview, I have a configuration error.

I again looked for the Z-Stick using ls /dev/ttyACM* and found the stick had “moved” to ttyACM1. Not a real problem, changing the line in configuration.yaml to usb_path: /dev/ttyACM1 fixed the error and I can see and control the light on the Z-Wave switch.

(I suspect that the Z-Stick was not properly ejected from the OS and upon re-inserting, the next available address was assigned by Linux.)

So, after rebooting the Pi, the USB device assignment was again ttyACM0 and the Invalid Config message was back. Edit the configuration.yaml file again and restart Home Assistant, and everything works again.

Am I doing something wrong or do I have to reboot the Pi when I remove the Z-Stick to pair it with another device?

Its better not use the button on the stick to do the pairing. Just add a node in the zwave config in hass.

It can happen that the usb path changes when unplugging the stick. You can make the name persistent to deal with this. Take a look at

http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices/

OK, I thought that I was following the official Home Assistant instructions… Turned out to be someone’s blog. I’ll remember that when I add more Z devices.

Interesting link- I did not realize that I could symlink hardware. I will use that- on another Pi. I have a cron job that backs up my MediaWiki data to a USB stick every night, and I worry that the USB stick could change from /dev/sda.

I had similar issues in the past and switched to this method about two months ago. Multiple restarts and even a pi switch without issue.

You can see my actual implementation here:
https://github.com/SilvrrGIT/HomeAssistant/blob/master/configuration.yaml#L155

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