[joakimsoderberg]

As I mention in the project I bought one of these: http://www.priority1design.com.au/shopfront/index.php?main_p...

Turns out the antenna that comes with it is way too small for anything other than manually brushing it against the cats neck knowing exactly where the chip is.

However I got some mails from another guy that built a cat feeder thingie. He ended up doing his own, much bigger antenna so that the cats head fit through it (he made a structure in cardboard wrapping the coil around that).

Anyway, he had some contact with the company, and they recommend using the RS232 version instead of the USB one for such applications... They had some better spec in some way.

EDIT: I looked up the mail, and to summarize he used 0.6mm enamled copper wire and a 120mm computer fan (minus the fan in the middle, that he wrapped the coil around. The reader then outputs the MOF value so you can know what frequency you're getting.

I've bought some copper wire myself and I'm planning to make a better antenna myself, but haven't yet.