I don't know if it exist but I decide to ask. This might be under alarm and security. I want to build something that would activate when im within a short range. I think the new lexus have something similar, as the person approach the car the door unlocks without pressing any button.
The system would work by using a very very short range transmitter and a reciever that would be on the vehicle. The receiver would sense the transmitter when its within 2-5ft. and activate a circuit.
This can be used to unlock and pop the door open at the same time, turn the light on in the garage when you walk in, unlock your tool box when you go for a tool and then lock it back when you walk away
