Hi ,
I would like to read multiple rf tags (30-50) passing by the reader (1-2 meter range). I also need to know the direction of movement (like a store security - going in or going out) so I guess I need two readers. I would like the tags to be as low cost as possible? What technology is appropriate? And where can I find hobbyist parts? Thanks,Amir
classic cheap/passive RFID has a range of a couple of inches.
Active RFID can do what you want, but the tags aren’t cheap and often need a battery.
Backscatter RFID tags need no battery but are more costly, like $2-5 ea.
Decollision algorithms for multiple in-range tags is quite complex, needs serial-number capable tags, and time in coverage, etc.
I’ve done a project with 1m or so passive RFID tag range, but the reader had to have very high power and needed an FCC exemption.