assignment 4

Electronics production

4rd week

The asssigment for this 4th week was to create, solder and program our own fabTiny board.

I chose the Valentin one, to avoid solder and de-solder the board.

PCB & Roland

In our Lab, we have the Roland MDX-40A milling machine.

We generated the file with the proper presets for milling the board trough fabModules.

It was "quite easy" to use, calculate the Z coordinate with the sensor and position the milling head. The main problem was that the boards were bended (even using A LOT of double-sided tape), the milling wasn´t uniform, as is seen on the picture:

We had to execute more than one milling file, being careful with the depth, for avoid breaking it, to be able to mill all the surface properly; increasing 0.10 mm in each pass; depending on the area of the board and the bending.

First, the traces with the 1/64 head and then the outline cut with the 1/32.

But, after a lot of suffering, we got them milled and cutted!


I´ve never soldered on-board components (only perfored boards), everything is smaller and smaller! But we have a great magnifying glass with light to avoid join paths and mess it all.

I only made the mistake of soldering two resistences in the wrong way, I messed it up a little bit because some components go on vertical and others on horizontal way; but I desoldered it quickly:

This is the good one:


We had at the lab an extra fabIsp programmed board, it was really easy to program following the tutorial; but the only problem I found is that the boards doestn´t fit properly on the USB connector. It is super tricky to find the right angle and position for the computer recognize it as a device.

It was almost a miracle being able to program it; my colleague Jose made the Andy board and he didn`t have this problem like me (it doesn´t fit properly too but It wasn´t so so tricky to plug it to the computer)

4 hands were needed to program a fabISP.

But I swear, I could program it, but now is very hard for the computer to detect it. On a Windows computer, it makes the classic USB Plugged in sound alert, but is not readable. I need to figure it out how to fix it, for next assignments. I´m going to try with an USB Extension cable.


I chose to made a new fabIsp, the fabISPKey model, Nuria gently gave us two already milled and cutted and I soldered it with sucess and It was my working fabISP programmer for all the upcoming electronics assignments.

Fabmodules Outline Routine

Fabmodules Traces Routine

Terminal Output


Shown how you made the board


Explained any problems and how you fixed them


Included a ‘hero shot’ of your board