Build the edge segments

• Grab two LEDs
• Bend one leg up by 180º on each
  (the same on both, e.g. the anode = longer leg)
• Align the LEDs facing each other
• Solder the bent leg of one LED to the unbent leg of the other, and vice-versa.
  The LEDs are now wired in anti-parallel.
• Repeat this process for the required number of edges for your polyhedron. (see table)

* Ensure that the distance between both LEDs is the same for all edge segments you build. A template placed below the LEDs while soldering might help.

Build the first face

• Align two edge segments' ends at the appropriate angle, to create the first vertex of the polyhedron. (see table)
• Solder the vertex
• Complete the first face by adding more edge segments until a ring is formed

Build more independent faces

Depending on the polyhedron you are building, you may be able to build more of these 2-dimensional faces before joining them in 3D space.

* The octahedron might be the easiest choice in this respect, as it has four independent faces which comprise all edges. Joining them should be relatively easy. I have not tested this myself.

(!) I did these calculations in my head without testing. Let me know if you find a mistake!

Let's go 3D!

Use the faces you have made, and add more edge segments to build up the 3-dimensional body of the polyhedron.

Program your microcontroller

Since it might be difficult to access your controller's pins once it is suspended inside your polyhedron, you should program it at first.

Wire it up

• Add a generous length of wire to each IO pin on your microcontroller.
  You can also use a socket for soldering and insert the chip later.
• Don't forget two additional (possibly longer) wires for power.
• Place the controller approximately in the center of your polyhedron.
• Route each piece of wire from its IO pin to the corresponding vertex on the structure.
• Wrap it tighly around the vertex a few times
• You can adjust the exact position of the controller by pulling it in the desired direction.
• In the end, all wires (except power) should be straight and taut.

Done!

• Add power to your creation and enjoy!
  Be careful not to mix up the + and - power wires.
• You may build or 3D print a base.