I’ve been using the USBtinyISP AVR programmer for some time now, to set the fuses, burn the boot loader, and burn the RF12demo.pde compiled sketch into each ATmega.

Trouble is, it’s slow as molasses …

So I got the AVRISP mkII programmer a while back, but the problem is that it’s unpowered. Not good for my setup, which expects power from the USB programmer:

So I went looking around for tips on how to bring 5V to pin 2 of the 6-pin ISP connector. Found this mod which uses a 5-to-3.3V regulator, and this one which draws 5V directly from the board.

I decided to tap the 5V USB power, but after the polyfuse, so that a short won’t damage the computer or USB hub as easily:

The connection is jumpered, so this can still be used in its original form when needed.

And then I spent ages chasing ghosts…

It turns out that avrdude needs a “-B 3” time adjustment to reliably program the chips. Now how am I supposed to know that!

Anyway, here’s the shell script I’m currently using on my old PowerBook, which automates it all:

That last character being echoed is a CTRL+G, i.e. an audible bell to signal when the process is done. It used to be essential, since the USBtinyISP took so much time for each burn. Now, it’s clocking in at 17 seconds, and that could probably be reduced even further by combining the three separate avrdude runs.

A roughly 10-fold improvement!