His solution makes it extra cheap by using so-called passive PoE, which injects a ... It’s also ridiculously cheap, with a PoE injector adapter (RJ-45 plug & 2.1×5.5 mm power jack to RJ-45 ...

IMPORTANT: This board strictly follows IEEE 802.3af Class 0 for PoE power delivery. Power injector adapters which just provide 48V or 24V passively without any negotiation will not work! (e.g. Unifi ...