This diagram uses the original Gemma but you can also use the Gemma M0 with the exact same wiring!
Above is the circuit diagram for the simple tiara. All ground pads are connected to GND on GEMMA, likewise all power pads are connected to Vout on GEMMA, and data lines are chained from D1 to the inward facing arrow on the first pixel, then from each pixel's outward facing arrow to the next pixel's inward facing arrow.
Strip the insulation from a long piece of solid-core hookup wire and clip it to one side of your headband. This will be the pixels' ground bus.
Insert perpendicular wires through holes in the headband and curl their stripped ends around the long ground bus wire.
Crimp wire connections with pliers.
Insert perpendicular wires through holes in the headband and curl their stripped ends around the long ground bus wire.
Crimp wire connections with pliers.
Be sure wire connections are tidy enough to nest snugly against the hair band, and solder connections in place.
Trim wires to the silhouette you like, then strip the ends. Bend the stripped ends over and hand the NeoPixels from them (through the pad marked -). Solder all NeoPixels, making sure they're facing the same way.
Solder wires from the + side of each pixel, and cut to length. Strip the ends and solder to one long power bus.
Connect power, ground, and data lines to GEMMA at the input end of the pixel chain. Plug in over USB and program it up! This basic sketch flashes the seven pixels randomly:
Get creative with your tiara design! This one uses a NeoPixel ring in the center, and the wiring is barely different than above.
