This is a USB AVR programmer based on the design by Thomas Fischl. I used the Eagle files by JA de Groot and changed them to suit a standard 6 pin Atmel AVR ISP header.

Schematic and PCB

In renumbering the components, the jumper numbers changed from the original. The functions of the jumpers are:

J1 Self Program: Set this jumper for flashing the ATMega(4)8 of USBasp with another working programmer.
J2 Slow Clock: If the target clock is lower than 1.5 MHz, you have to set this jumper. Then SCK is scaled down from 375 kHz to about 8 kHz.
J3 Board Power: Supply target with 5V (USB voltage). Be careful with this option, the circuit isn't protected against short circuit!

The Eagle files can be downloaded here.


The software is not mine. You get the software from the author's website.