What I am trying to accomplish: I would like to have a single Arduino Nano in a stationary position and many other nodes moving about. When any of the moving nodes gets within about 1 ft of the stationary Nano, I would like them to communicate until the moving node exceeds the 1 ft distance. I say node here because there are many different possibilities for this situation. The node could be a second Arduino Nano, or something like a passive rfid tag.
The communication could be very simple or very complex. At the basic level, the moving node just needs to announce itself to the stationary Nano when the two are within 1 ft of each other. This would lead toward using rfid, as there doesn't need to be much communication beyond identification.
So, the question is: Is there a way to do this cheaply and consistently? Is there some device that will allow for the moving node to identify itself when it gets within a range of 1 ft? I know that in theory rfid can definitely do it, I am looking more for a system that already does it.
In testing with some of the Arduino rfid readers and tags, most that are of a moderately small size and relatively cheap only have a read distance of a couple of centimeters.
I have also looked at straight RF communication between the stationary Nano and the moving node, such as using nrf24l01+ transceivers. This does not work as there range cannot be restricted to the proper distance. But if there was some sort of transceiver that could work at that distance, that would work as well.
My greatest hope is that someone knows of a small RFID reader that can be connected to a Nano and read a tag at a 1 ft range.