Very simple proximity activated switch (several inches range)? Answered
Hello Instructables! I am looking for a simple electronic switch that will instantly turn on when it comes within a few inches (5-8) of a little beacon or antenna of some sort.
I would like to be able to have the beacon be small, and preferably flat in form factor, with the receiver/switch system being no larger than an inch square. For size constraints, watch batteries would be the most preferred power source.
Would RFID be a good option for this?
Preferably I don't want this to have to be hooked to a phone, and it would need to be something that I could conceivably make a PCB foror use a very small existing board like a TEENSY.