Happy Pi Day indeed!

With the Raspberry Pirate Radio, makers of all skill levels are exploring what is possible with their Pi. More than just a single-board computer that for most requires a familiar desktop GUI, the Pi is also capable of being the brain that drives projects. In this case transmitting FM radio. As simple as one wire and a readymade disk image, it’s possible to have this up and running within the hour.

Beyond that there are already makers forking this project to meet their own experiments and requests for developing this project further. For example adding PLS and M3U support (check!), adding streaming internet radio support (also check!), allowing mic input (simply uncomment the microphone portion of the script), adding bluetooth functionality (we’re looking into it), and multiple requests for adding a bandpass filter (anyone want to take this on?) between the Pi and antenna to filter out harmonics.


After the project hit the digital airwaves some Windows users specifically got stuck modifying files on multi-partioned SD cards, for which our own Sam Freeman and Wynter Woods wrote a how-to using the free and open-source WinSCP (scp/sftp) software.

Others, with as little as a jumper wire and some scotch tape were broadcasting within minutes:

Meanwhile one user reflected on their past, and how the Pi provides the same solution to FM transmission they experimented with years ago:

Before I got an FM transmitter, my solution was a full-size Pentium 2 desktop in my trunk set to auto-start Winamp when I turned the 12V inverter on (after the computer booted for five minutes).

I soldered conductors from a piece of Cat5 onto the circuit board traces in an old keyboard, wired in parallel to the key switches, and also ran one of the twisted pairs to the system’s power button. The keyboard ones were for the Winamp hotkeys (B and V, I think, for next/previous track?), and then ran the Cat5 to the front of the car, where the other end of those wires got soldered onto the circuit board traces of an old ceiling fan remote in a similar fashion.

Was totally jank, but worked, until the hard drive died from all the road vibration. I even put an old Linksys wifi router in the trunk with it, so I could put new music in the shared My Music folder copied from my laptop whenever I updated my collection.

One reader commented, “I have to wonder how well this would work as an APRS transmitter when used with a proper filter,” while another was reminded of the Pi’s ability to act as a WSPR transmitter.

All fascinating stories and ideas.

Lastly there’s the issue of “illegal” vs legal. I’m no lawyer – there I said it – but I do know that reports of “federal agents” knocking down doors and arresting people for powering up this project is outright hyperbole. In the United States, by the FCC’s own documentation, between Jan. 8, 2003 and Feb. 18, 2014, written notices “informing a party that radio stations must be licensed” outweigh “a preliminary decision by the Commission or the Enforcement Bureau on delegated authority proposing a monetary forfeiture against a party” by nearly 10:1. In other words you’ll be told “stop” first and then fined. But not arrested by “federales” and all your life possessions seized. Reports of the latter are greatly exaggerated. Yes there are rules. We’re not saying there aren’t. But for one the culture of making is an international culture and FCC regulations aren’t the only regulations. Additionally the Pi-as-Pi is FCC-approved and here we’re showing what else is possible with this device. Remember, if you can’t open it you don’t own it, and that applies to software as much as hardware, and in this instance both.

As always if you build this project as-is, develop a custom enclosure to reflect your Pirate Radio’s personality, or modify it to suit your needs, send us a story of your experiences along with some images to [email protected]

Have fun making a have a great Pi Day y’all!