Just looking for some previous experience and thoughts on passive proximity sensors.
I am trying to create a system at my desk that recognizes ME as being ME within a range of 12" or so.
I have thought about RFID but since I need the identifiable piece on my person to be passive (does not require power) I feel that range will be severely limited. My ideal situation would be to have a small passive RFID tag embedded in a shoe and the reader would be placed near the floor.
I've also thought about using a rare earth magnet and a hall sensor but I think the range is an issue again.
Have you tried using RFID with a larger coil on the base unit? Turns adjusted to get the same inductance.
A magnet and hall effect sensor is going to have a -really- short range. Inches.
A radio antenna has a better reception when I touch it. The human body improves radio reception better than an alligator clip and five feet of wire. If only one could harness the antenna enhancement qualities of each individual, then a personal ID could be approximated. I remember watching a TV show with bad reception, but when I held the rabbit ears antenna, the show came in clearly. But when I walked to the couch to watch, the reception was bad again. Maybe you can improve this effect and have an ID signature antenna effect. Is there an app for this?