Our second assignment was to make a "Hello World" Printed Circuit Board (PCB), that would send a text string using the serial port of a computer. This picture shows the schematic of the circuit

This picture shows the layout of the PCB for the previous circuit. The board can be done in several different ways. For this assignment I decided to make it using the Modela mill.

In here you can see the Modela milling the PCB on a copper-coated board.

After milling the board, the only thing left is to solder the components, and program the chip...

   Ok, now to the REALLY tricky part. We needed two cables, one for the serial communication with the PC and a parallel one to program the chip. The parallel cable was fairly straightforward, we just soldered a clip to one end of the cable and a parallel connector to the other side. The serial cable though was a little bit trickier because of the small white plastic connector which needed several attempts (>5) before it worked.

This picture shows the code for the AT Tiny15 microcontroller used in the board.

A special thanks to Ayah (for helping me to program the chip) and Christine (for setting up the environment), without them this would have been impossible!
...And since my laptop does not have a serial port, I had to use a usb-to-serial converter shown in here.

This is the end result: a screen full of characters! Hey! what did you expect! it is only a "Hello World" project!

It is actually echoing the characters received by the microcontroller and showing them in a terminal window created by python.

And finally a picture taken on some weird and forgotten Sunday at the Media Lab's lower level at 2:00 AM... (Those crimpy metal things!)