http://fabiobaltieri.com/2011/09/02/usb-key-avr-programmer/
This project is an AVR ISP programmer with USB interface in a compact usb key PCB. The project is based on the original USBasp version of Thomas Fischl, which can be found on:
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.
COPYING text version of the GPL
README this file
binaries/ pre-built firmware images in hex format
firmware/ source directory for firmware files
hardware/ source directory for the hardware design files
Building requires an avr-gcc toolchain, in the firmware/ directory, to build run:
make main.hex
Flashing the firmware on the device requires avrdude and a compatible hardware programmer. Default configuration is stored at the beginning of the Makefile. To program with the default configuration, run:
make flash
Fuses can be configured running:
make fuses
All hardware files (schematic, layout and libraries) are in CadSoft Eagle format.