Hello!
Now I see better what you want to do.
Beware that a simple copper loop (or let's say a flat coil) can transmit wireless, but the problem
will be the disance. Forget about 15m! If you can reach 15mm, it will already be a performance.
Now if you want some very simple transmission mean, why not using IR led? This way, you can
reuse your TV (or any other) remote control. For example the remote contreol of your old TV that
you just trashed.
Advantages: it's quite easy to use, easy to implement. If you just want to detect whether a button
has been pressed or not, you can do it with a plain IR receiver, even without microcontroller.
Now if you want to decode which button has been pressed, then you need some logic and a microcontroller
might be one good solution. There are cheap TI boards around 10 ~ 15 USD that can do that
without too much trouble. I have published some source code for a custom board, but this can be
reused with any TI MSP430 board with minor modification. If you look for C-01 LED blinker,
you should find it. Not only code, but also explanation of how / why it works. There are about 15
sources right now. I will add an infrared source code, that's a good idea (my custom board has
an IR decoder). By the way, it's called ReoBoard. Stay tuned!
Dora.