10/24/2005

MAS863 | Fall 2005

Assignment:

Create the Hello World PCB.

Project:

Create a PCB.  This assignments aligns quite well with my final project as I will have to make a fair number of PCBs.

• Choose Modela or the Vinyl cutter to create the PCB.
• Stuff the board with circuit elements.
• Build a Serial and a Parallel cable to program and test the board.

Tasks:

• Open the hello.cmp file provided with CAM.py tool.  Ensure settings for tool speed and depth are as detailed in class.  Contour, Raster and create hello.rml tool path file for the Modela machine.

• Mill the PCB using the Modela milling machine, vacuum clean.  I had some difficulties with this step due to several problems.  One of the set screws holding the bit was slightly stripped and I believe is slipped during cutting.  Several attempts resulted in too shallow cutting on the left side of the PCB and deeper cutting on the right.  A potential cause was a warped board that was not remaining flat even with lots of tape.

• Cut board out using scissor cutter.

• Stuff the board.  Best results on soldering using the fine tipped soldering iron.

• Make cables for programming.  Making the serial cable was extremely difficult in that the I struggled for a long time trying to put the Molex connector in upside down.  Once this error was corrected things were a lot easier.

• Program and test.  Run the AVRDude command line.  A steady hand and coordinated technique to hold the cables in contact with the ATiny leads is essential to making it work.  If there is another pair of hands around it is the best solution.