For this week assignment, I really wanted to make a multitouch-pad. I started with Neil's Step Response example (transmit-receive). I milled and stuffed the board.

Programing and using the python visualization was easy. You can watch the result in the linked video.

Then, I started the more complicated part of the assignment - understanding how to make a multitouch-pad. I began with a tutorial by Matt Keeter. I followed his schematic and then tried to arrange the pads on the same side of the electronic components using traces instead of milling a two-sided board.

It was pretty complicated and probably demanded more knowledge in electronics then what I have so far, or simply more time....So, I tried to create a simpler version

Following this tutorial I built the schematic in Eagle. The logic is an input from a single pin on the attiny44 and output from 8 different pins which creates 8 different pads.

Tracing the board took quite a while, because I wanted to leave the pads area clean from traces and not to use too many jumpers. I tried a few configurations. At the end I decided to connect the traces to the pads by wires on the bottom side of the board. (Thanks Diego P for the great advice!)

I prepared the png files for the modela in Photoshop. I used 4 different files: 1_Traces for the electronics components. 2_Traces for the pads, in which I changed the number of offsets in the Fab_module to -1, in order to remove all the copper between the pads. 3_File to drill the holes for the connecting wires. 4_ Interior file.

The board after milling.

Soldering + Wiring

In order to program the board I used the tutorial's C + makefile as a base.

Checking all the pads on the serial monitor. Watch video

Still working on the visualization... Hope to update soon!

Thanks to Diego Pinochet and Matt Edwards the TA's for all the assistance and advices :)