I have been looking for my lost car key. I have RTL-SDR and I am able to listen to key fobs frequency which varies between 350-444MHZ. I was trying to understand how most of the keyless entry systems work but I'm not sure whether:
- Key fob detects a car in proximity and requests and exchanges information
- Car detects key fob, meaning key fob must be emitting signal once in a while.
Obviously, I would be able to locate the key if the key fob is emitting a signal. Problem is, the key has been lost at a pretty large property and is the only one I have, so it's quite a pickle.
RTL-SDR easily picks up other car key signal with buttons.