If you’re using OPNsense I recommend you install and enable Avahi to help route discovery traffic, and I would double check multicast is functioning on your wifi.

IIRC with home assistant there are some commands you can run to make it aware of your VLANs… have a look at this

is multicast DNS enabled and available in that VLAN?

have you set up the network for HA using the

ha network 

commands?

have a look at the Shelly H&T (and the new G3 version). They are cost effective battery or mains powered temperature sensors that include both bluetooth and wifi. They work locally with no hub required but can also report to the cloud where alerting can be configured.

i’m managing to make enough aluminium with three refineries and three foundries for now. one water pump is enough, the waste from the other factories keeps it all going.

Ada said it wasn’t worth listening to, and in fact they had tried to destroy all copies, so I didn’t listen to it. I don’t want to upset Ada.

I meant the one on the left but ok

who’s the cute one?

definitely run two cables for each point. nothing beats having a cable be broken somewhere in the walls with no way to repair it.

You can get that kind of power through a Cat6a or Cat7 ethernet cable but a lower spec cable won’t work. here’s an article that talks about the limitations https://sixtytrend.com/can-cat5e-do-poe/

I’m using PoE Extractors to run some regular 12vdc stuff using existing ethernet cabling.

A couple of points to note:

• network switches won’t turn on power by default unless the receiving device asks for it using the right protocols, so you need to inject the power using the corresponding PoE injector at the other end of the cable. you can’t just snip the end off a RJ45 and wire it into things.
• Cat cable won’t take high currents, be sure to stick within the allowed range for the cable or it will melt and maybe bust your device
• there is a voltage drop over distance, be sure to calculate if you need to change your transformer as 12vdc could become 9 or lower by the time it gets to your device
• there are some really poor quality PoE injectors/extractors.
• running mains cable and having a transformer nearer the device might be simpler and cheaper in the long run.