Like any other electro-mechanical-engineeringly inclined hobbyist, I've spent my fair share of time drooling over the promotional videos for products like Solidworks or Zuken CR8000, but I'm still always excited by what can be accomplished with cheap and mainstream tools like DipTrace and Sketchup.
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Today I started to put together the first stages of the design I am planning to use for my Raspberry Pi shield.
There's no electrical schematic yet, but I've chosen some of the important components and with about 4 hours of dithering about with dimensions and feature snapping and such, a fair amount of the groundwork was done...
SketchUp was first used to create a 3D model of the RasPi with accurate dimensions (I hope!). Then this was used as a template from which a basic PCB outline for the shield was generated, again with dimensions that should correspond to the RasPi anatomy.
Then it was over to DipTrace to start preliminary work on the Schematic and Layout designs. The second picture here shows the Layout with the four Propeller QFP chips (P8X32A-Q44) laid out in a vaguely sensible location on the shield. In the middle is the DS1077 programmable oscillator which (if all plans go well) will provide a solid clock signal for all four Propeller chips to operate from. I've not yet decided on how I' going to organise EEPROMs on this board yet. I'll probably provide two 64KB eeproms shared between the four Propellers. As for extra RAM, I'll am thinking about using some fast SPI SRAM chips (one per Propeller) to supplement the on-silicon RAM in each chip.
There's a huge amount of work to be done before I get any prototypes made but that's all part of the fun.
But this is all fairly trivial to do even with modest tools within reach of the serious hobbyist. But that's not to say I won't still be pining for a copy of Solidworks to drop through my letterbox one day :)