I'm trying to decide whether it would take less time to make a new RFID reader using an antenna from an existing unit as well as using the code (to produce the fsk signal) as well as the circuit used to match the antenna's resonant frequency. The existing unit is made of an antenna made out of coils of lacqured copper wire. There is an existing unit including the firmware codes for the microcontrollers on the unit, but it doesn't talk properly anymore to the computer. It's also built for a slightly different purpose too. It's built to periodically check for the presence of a tag and then report to the host computer. I'm trying to get it to communicate either to another microcontroller, or to the host pc and have it coordinate between talking to two separate microcontroller systems. I'm also thinking of building a new one with a separate microcontroller system or RFID reader, adapt the code used for the existing system and have it to talk to the host computer. I'm wondering in your opinion, based on the information that I have found so far, whether fixing the current system in terms of hardware and firmware-wise despite its reliability issues or building a semi-new one adapting some of the circuits and code of the existing reader would be the easier and more reliable solution. Sorry if I still sound vague, but your views would be much appreciated as I have more point of views to work with.