micro - USBasp

This is a work in progress.

• Port of USBasp to ATtiny 85
• Design of optimized hardware

Why?

• It's fun.
• USBasp is a de-facto standard for small USB-AVR programmers. It's the only one to support TPI.
• Porting it to ATtiny85 allows for a smaller and cheaper circuit. Cheaper MCU, no Xtal, etc...

This software is based on Thomas Fischl's USBasp. See readme.txt for original comments.

Status

Software:

• USBasp sucessfully compiles for the ATTiny85.
• micronucleus works as a bootloader.
• USB device is recognized as USBasp and communicates with AVRdude.
• Software tested on microUSB hardware. Both TPI and SPI seem to work.

Hardware:

• Revision 0.5 sent to OSH park for pcb manufacturing.
• Update v1.1 done, ready for manufacturing.
• Update 02/08/2013: All parts received, first device built.

Flashing

• Flash micronucleus
• Set the fuses as in thuis Makefile: HFUSE=0x5d, LFUSE=0xe1, EFUSE=0xfe
• Flash the firmware with micronucleus

Hardware

Circuit:

v1.1 PCB front side:

v1.1 PCB rear side: