Raspberry Pi can broadcast FM audio signal
This may be a bit beyond many broadcasters here technically, but it sure is cool. The Raspberry Pi, that tiny little computer for hobbyists and tinkers is capable of generating an FM signal. It's a hack and the software is a bit limited so far.
Total output on this is estimated at 14mw.
http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter
That solution is limited to a mono broadcast.
Someone outdid them and created a stereo version 🙂
http://www.reddit.com/r/raspberry_pi/comments/14k5o3/raspberry_pi_fm_transmitter_with_no_additional/c9mt1l5
There are multiple videos on YouTube about this:
Hmmm! FM pie!
Hey, I see big future for the little Pi.
If it can do FM, why not AM or shortwave?
There are easy to make RF amplifier stages using single transistors, and maybe a Pi could be wired up to provide a spectrum analyzer to observe harmonic frequencies for compliance.
My first Raspberry Pi project is going to be a remote control center to monitor and control all my part 15 transmitters!
I am unsure what the Pi packs that allows for this hack. Supposedly what is on board isn't in the FM broadcast range but works.
It is a tad quirky and supposedly far from great/clean. But it does work.
I threw an alligator clip with wire on the pin, compiled the software, converted and audio file and presto it works, with obvious quirks.
It works well enough to be heard in my entire house (big house and multiple stories).
I suspect the Pi can do the same magic on other frequencies, AM band? Unsure. Would be interesting.