I bought 3 Ubiquiti UniFi access points (at enormous cost) to try to deliver reliable wifi to all points of my oddly shaped home (long and thin with some thick brick walls that mask all radio signals).
I’ve installed the Java & MongoDB(!) software needed to run it.
However at this point the AP is resolutely unable to contact / be seen by the controller software, and there is no solution in sight. Turned out to be a firewall issue. Just opening the documented ports wasn’t enough — to associate, I had to disable the firewall, and then reenable it after association.
The UI is quite cute: You can plop down access points on top of Google Maps (I have only one AP plugged in so far):