DIY ATtiny45/85 ISP Header

ATtiny ISP header in practice

A quick weekend tip for a change, I thought to share a nice small soldering project will make programming ATtiny45 and ATtiny85-based projects a flash:

Basically I took a piece of veroboard, soldered some extra long pin headers on the bottom so it will form a tent of sorts above a ATtiny45/85 attached to a breadboard project. Then I soldered a 6-pin header to attach the ISP programming cable to, and used short pieces of jumper wire to route the header pins to correct ATtiny85 pins.

Now whenever I need to flash a ATtiny45/85 project sitting on a breadboard, I can just put this on top of that and never need to look up the pin layout again!

DIY ISP header closeup

You can click the images for larger versions. I’ve also been quite busy with my PS/2 projects, so I have some nice material to share regarding that when I have some free time again in my hands!

Tips and Tricks: Flashing already soldered MCUs

I have been wanting to try this one out ever since I soldered together my USB password generator six months ago, just to realize that I would’ve actually liked to make a few changes to the firmware. The problem with my design was, that I had managed to pack everything so tightly, that there was no hope of reaching the ATtiny85 pins via normal methods to reprogram it.

I initially tried to use a 8-pin DIP socket and press it against the MCU, but it soon became apparent, that I could not keep it stable for all the pins to keep contact long enough. Lacking proper microhooks, I had to postpone the idea shown in the above photo until I just recently put my hand on this set of IC hooks from SparkFun.

The five IC hooks came one hook short of the six needed by the ISP header, but fortunately/unfortunately one of the pins was impossible to access even with these tiny hooks, so I manually held a yellow jumper wire against the MISO pin while running avrdude. Did it work? Look for yourself:

Definitely not rocket science, but for $4.95, I’d say it’s a pretty good deal!