A little specific, but some TP-Link routers can trigger one of their devices when a MAC address connects to them. I have their Deco M5 mesh system and it has this. Previously they supported IFTTT and I was triggering presence that way. They dropped IFTTT like most manufacturers are starting to, and so I needed a local solution.
They added automation capability to the Deco M5, but the catch was I would need one of their devices to trigger. What I ended up doing was buying their 3 outlet Kasa power bar, but I could have simply bought one of their Kasa Plug-in Smart Plugs for $10.
I sense presence like this:
- When our phone MAC addresses connect to the router, their automation turns on the Kasa outlet (no device plugged into that outlet).
- I'm using this community driver, but since there's a possibility of lag on the hub from auto refresh, I have that disabled.
- When we approach the door, my motion sensor (which is used as part of my presence detection rules) starts refreshing the Kasa driver every 1.5 seconds for 10 repetitions and then stops.
- The brief refresh of the driver is enough, and that ON status is my presence indicator.
- After 1 minute the TP-Link "Smart Action" turns the switch off again.
While the mesh router itself requires a cloud connection, I don't think the control from the router to the outlet uses cloud. Maybe some components of it do, but it's far too fast to be pure cloud. I do think their Kasa app on my phone does use pure cloud though, as it's a little bit delayed in controlling it.
