A short history of RFID for model railways.
Please contact me if you think other things need to be added, to give other hobbyists a more complete view.
There is a video here of a RFID system by Steve Davis, based on the above.
It is well worth reading this article, and I am grateful to Seth Neumann for giving permission to download the article here.
MERG has been doing some fine work in RFID, making the IDLA12/IDLA20 readers available, and doing a concentrator for up to 8 readers into CBus. There has been a lot of discussion on the forum on how to implement it, and recently much work has been done on trying to use the RC522 as a reader, with some success.
For whatever reason, RFID seems not to have taken off as a mainstream technology for hobbyists. There are obviously quite a few hobbyists working away on it, but they all seem to be trying to adapt technology used in other areas, and applying it to modelling. To my mind, RFID has great potential, as it can be used not only to identify rolling stock, but also for block occupancy, feedback for automation systems, Train-on-Track-Indication - all of which need separate systems at present. Hence this attempt to design, from scratch, a system specifically targeted for model railways.