Help with ititial design and physical aspects

Hi,
Could I ask for some advice please on design I am planning.
We currently have some ‘automation’ based in a HAI Omni controller but that device is getting old and bits keep failing (And the whole HAI range has been discontinued).
I was hoping to remove everything from the Omni except Alarm functions in the 1st instance.
It currently has:

  • Half a dozen UPB Lights and Switches
  • About 7 PIR sensors
  • major outputs are a series of watering system controlled by relays.

To this I hoped to add Alexa and possible voice commands for the old devices and all kinds of new ones based on Z-Wave (or similar)
ie bring it up to date but dont re-wire the house.
Home Assistant of course jumps out as an excellent solution - especially using Raspberry PI which I have lying around from previous projects.
It looks like all the old stuff is covered with existing ‘integratons’ but I am having trouble conceptualising the physical layout.
Currently everything routes through a cabinet in the garage (ie all the PIR enter there; all the watering relays leave from there because their 24VAC source is there)
All the internet (RJ45) points also fan out from there.

When it comes to Z-wave though - looks like there are a variety of USB Sticks recommended.
I am assuming these Sticks communicate with individual Z-wave devices - have I got this right ?

But if I put the Stick in a steel cabinet at one corner of the house I dont think it will be communicating with much.
Does anybody have any suggestions for this eg

  • maybe an external Z-wave controller that can talk to Home Assistant over network ?
  • a Z-wave stick with an external aerial ?

As I am just starting the journey any help would be greatly appreciated. I am not even sure I have this in the correct Category!
Thanks
JC

Z-wave (& zigbee) rely on a wireless mesh network, I.e. you really need to build a wireless network (of mains powered devices) using one or both of these. So normally you would have a stick [gateway] (USB dongle) that then communicates to one or more Mains powered devices (on the same network) that then repeats these signals to other devices further away (don’t get z-wave & Zigbee confused with each other, as they are very different. And don’t get wifi confused as it is very different again).

Thank you DefenestrateIT,
Thats has confirmed my understanding was substantially correct.

Any idea how to get the dongle signal out of a steel cabinet ?
JC

What do you mean steel cabinet?
I have one in a Steel Rack cabinet, & a few meters away I have a Aeotec Range Extender 6.
But any mains powered z-wave device will act as a Range Extender. The biggest mistake people make is just getting battery operated devices, & they won’t act as repeaters. Some devices can be both, but they will only act as repeaters if they are plugged into mains power at set-up.
Most people start with zigbee light bulbs, & thus creating a good zigbee mesh network, but z-wave light bulbs aren’t as popular.
I have a few z-wave devices in a steel shed, about 20meters away from my house & that was hard to get a signal into, but after installing a lot of mains powered z-wave devices it can now penetrate the insulated steel walls.
z-wave is generally more expensive than zigbee, because of licensing cost on z-wave. But I don’t know of any zigbee smart-switches that monitor power usage, so z-wave Smart-switch are really good for this (& they act as repeaters).
A lot of people use a USB extension cable (because you shouldn’t have a zigbee & z-wave gateway close together). If you can’t get a signal out of your cabinet, perhaps you should try this.

P.s. If you are going to use a Raspberry Pi (I do) Read this first: Don’t use a SD card

Its a cabinet mounted on the wall where all this ‘stuff’ goes. Sounds like just using an extension cable will get the signal out of the faraday cage - then like you say it just needs some device reasonable nearby to get the ball rolling. And I hadn’t got that far yet but timely advice on SD cards for the PI. I think I learnt that lesson with a dash cam - the card needs to be written to A LOT, and only written to. You only ever read from a dash cam when something bad happens.
Thanks for the help
JC