How

Tiffany Cheng

Made [almost]

Anything

Electronics Production

This week's assignment was to make the FabISP in-circuit programmer. I chose to fabricate Valentin's PCB design because it uses a board edge USB connector instead of an additional component (that alone makes it look way cooler), has a hole for putting on a keyring or necklace, but best of all, disconnects the USB blocking by snapping off once the fabISP is programmed with its firmware (instead of soldering jumpers and desoldering afterwards -- a much more elegant life cycle design).

  • Milling Machine: Roland Modela MDX-20
  • Material for trace: FR1 (phenolic paper)
  • Tool Diameter: 0.35mm
  • Number of Offsets: 2

The process is pretty straightforward, but it took me several tries to route the PCB. My first time, it appeared that the surface was not quite level which led to portions not completely removed. The couple times after that, I played around with FabModules' settings to get the copper connections right.

After routing the board, I soldered the components. It was my first time soldering such tiny things! Some components flew out of my tweezers. The heat gun is very useful for removing incorrectly placed components (which happened a couple times while I wasn't paying attention to the polarity and orientation within the circuit).

I think I did a neat job! It looks shiny and chrome. Man, those copper pads and components are small.

I inserted it into my laptop and checked the circuit with a multimeter... all connections seem to be fine. Using an existing FapISP, I tried to write the firmware to the ATtiny on my own FapISP, and got thanked by terminal.

So I tried vinyl cutting too. I drew this circuit in Rhino, took it to Illustrator, and exported that PNG. I made the circuit bigger (making sure to keep the components' copper pads the same size) for the vinyl cutter's physical limitations.

The thin lines are very delicate. I took care in lightly etching the circuit multiple times so as to not rip the copper apart.

I started to have too much fun with cutting vinyl. Since my How To Make website currently has a Star Trek theme, why not continue that on my notebook?

Now my laptop proudly displays the seal of the Twelve Colonies!

up!