I’m late to the game, but I bet I’m not the only one. It turns out that there’s a very easy way to set up your old (version B, and presumably version A) Raspberry Pi as an FM radio transmitter. Here’s how I did it and what I used it for.
I received an Arduino Uno for Christmas this year, so my Dad and I spent some of the holiday time doing some projects. His job was to get a circuit built implementing a 74HC595 Shift Register and my task was to set up some RF communication. Dad completed his project before I did, but as I’m on vacation all this week, I was able to finally get something up and running.