Controlling Griffin's RocketFM under Linux (rocket.c)

I'm using modified version of Michael Rolig’s shark.c (original mirror)application to control my RocketFM from Linux and I released the new tool rocket.c. Hidapi version: rocket_hidapi.c Owners of Griffin's RocketFM now can control this little FM  transmitter under Linux.

Avaliable options:

  • Changing frequency from 88.1 to 107.9 Mhz (but You can use range from 70 to 120 Mhz).
  • Changing transmitting mode (mono/stereo).

So how to get RocketFM working under Ubuntu/Debian?

  1. Plug the RocketFM in the USB port, you’ll get this in dmesg:

    usb 1-6: new full speed USB device using ohci_hcd and address 2
    usbcore: registered new interface driver hiddev
    input: Griffin Technology, Inc. RocketFM as /dev/input/input6
    input,hidraw0: USB HID v1.00 Device [Griffin Technology, Inc. RocketFM] on usb-0000:00:02.0-6
    usbcore: registered new interface driver usbhid
    /build/buildd/linux-2.6.24/drivers/hid/usbhid/hid-core.c: v2.6:USB HID core driver
    usbcore: registered new interface driver snd-usb-audio

  2. Install libhid-dev from repository's:
    # apt-get install libhid-dev
  3. Download rocket.c
    # wget
  4. Compile rocket.c using
    # gcc -g -o rocket -lhid rocket.c
  5. Copy rocket to /usr/local/bin
    # cp rocket /usr/local/bin
  6. Check that executable is working:
    # /usr/local/bin/rocket
  7. Turn on your favorite player (xmms, mpd, amarok or gnomad) and let it play to usbaudio device.
  8. Change your station frequency:
    # /usr/local/bin/rocket -freq 102.7
    Or if you want to stream mono sound:
    # /usr/local/bin/rocket -freq 102.7 -m

Inside Device:

  1. UAC3556B (usb audio processor)
  2. 24LC128 (firmware & config for usb chip)
  3. BH1415 (FM TX chip)


  1. The hardware design allows us to switch on/off blue light, but I have not been able to realize it, I think that problem is in firmware.


Brent (not verified)

Thu, 09/25/2008 - 03:08

This is awesome! Exactly what I was looking for. Is there anything special I need to do to stop using the RocketFM transmitter? Say I'm using it and I decide I want to use my computer speakers or the line out. Do I just unplug the RocketFM from the USB port? I'm guessing I'd at least need to switch my software music player to a different output device. Thanks!

Kate (not verified)

Tue, 07/07/2009 - 03:05


First of all, thank you! I've been looking for a tool like this, and it seems perfect for what I need!

One little problem, though - I'm getting an error

"hid_force_open failed with return code 12"

when I try to change the frequency. Do you have any suggestions on how to fix this?

Andrew (not verified)

Thu, 11/26/2009 - 04:22

Awesome! Just what I have been looking for, set this up on my netbook and allows me to DJ at parties to existing radios keeping my system a safe distance from unwanted accidents. Thanks a bunch!

Sam (not verified)

Sun, 09/11/2011 - 03:06

Thank you very much for that.

For anyone on Ubuntu 11.04 (not sure about other versions), libhid-dev seems to be missing from the default repos.

I downloaded it from See the dpkgs in the .tar.gz attached. I also had to install libusb-dev to install those packages.

To get my applications to use the RocketFM device, I also installed Pulse Audio Device Chooser as per this thread Works well.

Again, thanks.