TURNIPSCHOOL is a hardware implant concealed in a USB cable. It provides short range RF communication capability to software running on the host computer. Alternatively it could serve as a custom USB device under radio control.

Status
A fully functional prototype was presented at ShmooCon 2015: http://www.shmoocon.org/speakers#usbtools

TURNIPSCHOOL PCB: https://github.com/mossmann/cc11xx/tree/master/turnipschool

USB Cable with the A connector cut off

3D Printed mold for overmold boot: https://github.com/kikithegecko/turnipschool-casing

Silicon overmold material: http://sugru.com/

C clamp

Cooking oil or other mold release agent

Optional: heat shrink tubing

GoodFET for programming: http://goodfet.sourceforge.net/
Suggested Firmware: https://bitbucket.org/atlas0fd00m/rfcat
Suggested Bootloader: https://github.com/AdamLaurie/CC-Bootloader

step 1: Assemble PCB. For operation near 900 MHz, solder one end of an 8 cm wire into the antenna port.

step 2: Wire GoodFET to PCB (refer to TURNIPSCHOOL schematic and layout and the pinout at http://goodfet.sourceforge.net/clients/goodfetcc/).

step 3: Install bootloader with goodfet.cc.

step 4: Use the bootloader to install rfcat or other application firmware.

step 5: Fully test both the bootloader and application firmware.

step 6: Solder wires from USB cable to PCB (refer to TURNIPSCHOOL schematic and layout).

step 7: Test downstream USB functionality.
step 8: Optional: Install heat shrink tubing around PCB to ease future removal of overmold boot.

step 9: 3D print 2 sides of the mold for the overmold boot.

step 10: Coat inside of mold with mold release agent such as cooking oil.

step 11: Form overmold boot around PCB by hand.

schematic: Dominic Spill (@dominicgs)
layout: Michael Ossmann (@michaelossmann)

overmold boot design: Karoline "kikithegecko" Busse (@kikidergecko)