Lately, the glass work on the physical box has been on pause since I realized I needed to work out what the connections to all the sensors is going to look like. To work out the electronics, I buckled down and started designing the circuit board. I had a vague notion of what it needed to do but it always helps flesh out the design when you really have to put it down on a board.

Previously, I’ve designed my boards in Eagle, which I bought back in 2010 or so. However, since then Eagle has been assimilated by Autodesk and its functionality is now part of Fusion 360. Strangely enough, while Fusion 360 has no limits on its capabilities for 3D design even in the free version, the electronics design retains a limit on the board size from the free version of Eagle. I can’t use my old Eagle license and Autodesk has now taken the standalone Eagle entirely to a subscription model which I wasn’t about to sign up for. Luckily I could, barely, fit all the stuff I needed within the board size limit in Fusion 360 (I think it’s 80cm^2.)

While the Fusion 360 Electronics experience feels like the 3D design experience from 4 years ago in that it crashes constantly, the integration is pretty cool. It automatically creates a 3D model of your circuit board that you can integrate into the 3D design. I haven’t made use of this yet but I will 3D-print the enclosure for the electronics so it will come in handy there. This way there’s no question of whether the board will fit and you can even make very funky board shapes if you need to squeeze the board in somewhere.

Designing the schematic is very slow for me, since I do this rarely enough that I basically have to look everything up all the time, but I just put in the order at OshPark so in a couple weeks I should hopefully have the board here.

A rendering of the circuit board from Fusion 360. Not all components have 3D models, so the connectors and some of the components just show up as squares.

Now that I know exactly how things will be hooked up, I can get back to putting the box together with routings for the wires.