Arduino Teaches Old Coder New Tricks

PCB Layout

When the .pcb file is opened with gEDA's PCB program and the commands invoked are listed in the gsch2pcb command-line text output, you are presented with a jumble of components. I first dispersed the components manually with an approximate placement and then activated the "rats-nest" display. The "rats-nest" is the connections that must be converted to copper traces. After shifting around components to visually bring the "rats-nest" connections to their shortest routes, I was presented with what you see in Figure 5.

Figure 5. Components with Associated Rats-Nest

PCB possesses the ability to auto-route the traces, namely convert the "rats-nest" into copper trace representations. This tends to do some odd things but produces a workable PCB design once a cleanup is done. I chose a semi-manual layout so I could control the placement and appearance. Basically, I used the auto-route for the power traces, did some manual cleanup, then used auto-route for the signal traces, followed by more cleanup. The result was similar to Figure 6, which is my second and final version of the layout for the ATtiny84 version of my VT100LCD project. PCB Manufacture Printed Circuit Board layout consists of applying upon a copper laminated board an acid-resistant pattern that represents the areas that are to retain copper after etching in an acid solution (etchant). Areas of the copper laminated board that are exposed to the etchant will be dissolved away, leaving the areas under the acid-resistant pattern intact.

Figure 6. Final Layout of vt1001cd84 Project