Just thought I’d share (i.e., show off an Arduino based project using all open source software, an rfid reader from ebay, and an xEMi [xEM Tag + Injection Kit].
$57 for the tag and injection kit
$12 for the door latch (ebay)
$8 for the rfid reader.
$20ish for the Arduino (I wire my own using an atmel328). The board is powered by a standard 12vAC bell transformer.
… and I use the standard flash library that comes with the Arduino ide to save the card codes for later lookup. A standard electrical box (like for wall switches, or sockets) is used for the electronics, with a blank cover. I drilled two hols in the blank cover for an, “erase” and an, “remember” code buttons. A couple LED’s provide feedback.
Nope, it’s just a cheapo HID-like (likely made in China) rfid reader from ebay. On the inside wall on the backside of the rfid reader in the video is an electrical box (from Homedepot) that contains the electronics.
I don’t think you need a genuine HID reader, but unless you buy something that explicitly says, “HID reader” it’s anybodies guess if it’ll work. The cheap, “EM” readers on ebay don’t read my HID cards.