91.548 Lab 3: PCB Design Tools and CAD File Formats

due March 3

This lab has two components. You will learn how to draw electrical schematics and lay out printed circuit boards (PCBs) using the EAGLE CAD software. Also, you will use understand and manipulate common 2-D CAD file formats.

PART ONE: PCB DESIGN AND GERBER GENERATION

1. Schematic diagram. Using the EAGLE CAD system, create a schematic diagram for your previously designed LogoChip project.

2. Printed circuit board layout. Using the EAGLE CAD system, while creating the schematic, choose the appropriate PCB patterns for the parts you are using. Position the parts optimally in inside the rectangular board area. When the schematic is complete, run the Autorouter to lay out the board.

3. Gerber files. After the layout is complete, create Gerber files for your design. Use Fred's EAGLE Gerber Output Instructions.

4. Preview the Gerber files. Use the program GC-PREVIEW from www.graphicode.com.

PART TWO: CAD FILE CONVERSIONS

1. Experiment with the file conversion application server at C. Scott's PCBMill Web Utilities site. Use the convert your Gerber files into HPGL (Hewlett Packard Graphics Language) plt files tool.

2. These converted HPGL files are tool paths for isolating traces on the printed circuit board. We need to convert these into CAMM-I commands for our Roland EGX-300. We don't have Roland Signmate, so your task is to figure out how to convert from the plt file into something that can be sent to the EGX-300 engraver. Strategies: find info on HPGL; read over the intro to CAMM-I; generate some shapes using the Roland EZ-Engrave software we do have, print those shapes to a file, and examine that file for sample legitimate CAMM-I code.

3. I created a software tool to convert the drd drill data files into CAMM-I instructions. See my printed circuit board tutorial. See also C. Scott Ananian's ideas for mounting blank PCBs in the engraving machine.