yan 🐇random n00by question: say that i have a key card and already determined that it's not NFC. what's the easiest way to figure out what protocol it is using? assuming it is passive RFID, is there a DIY way to read it (like with an SDR)?
chris@bcrypt sort of, but there are a lot of things to figure out. being RFID it's powered by an inductor which means you'll need to match freq for it to power properly, and once you power it you have to figure out what frequencies it's using. the real trick will be that it's using near-field propagation so common far field antennas may not work as expected.