Wednesday afternoon, the teachers suggested that we make the icosahedron bigger while keeping the same amount of LEDs. This avoids packing the insides together too much, and holes in the PCBs will improve cooling, which is even more important than we previously thought because we messed up the consumption estimation (too low).
The new sphere will have a 35-ish cm diameter (triangles have 18.5cm sides now). I’m currently changing the way we place LEDs: before, we specified spacing constraints and our OpenSCAD program would then put as many LEDs as possible on the triangle. That’s no longer what we want: we want a fixed number of LEDs on the triangle, and the program’s job is finding the layout. For instance, one can specify a number of rows and a different number of LEDs for each row.
When I’m done with that, I’ll print the triangles on paper as a check and then perhaps build a full-scale model with them (thin cardboard will do the trick, I think). It’ll be useful for designing the inner structure, checking that the LEDs layout is uniform enough, and of course, cluttering our desks !