chebe: (BeautyQueen)
chebe ([personal profile] chebe) wrote2015-08-25 08:08 pm

NeoPixel Tiara

I love the Adafruit Learn site, particularly the wearables section, there are some really fun ideas in there. And when I saw the NeoPixel Tiara I knew I needed one. I had almost everything already, except the 3d-printed band.

To TOG! We downloaded the thingiverse file (tiaraHolesClose.stl), converted to gcode, and watched the LulzBot Taz print for 50 minutes. *cue montage music* It was a pretty good print, given how fine some of the detailing is, but our process needs tuning as there are artifacts, and the strands are coming apart as I touch them. Still, usable!

LulzBot Taz 3D Printer part way through printing the tiara

Robot minion making me a crown. Finally.
Photo by chebe



On to the assembly! I mostly followed the tutorial, but made a few small changes.
(1) I saw no reason to have the power rail run along the top like that. I decorated each NeoPixel with a faceted bead, and then twisted the power wire with the ground wire to (a) make it slightly more decorative, and (b) to make the wire uprights stronger.

NeoPixel with ground and power wires twisted together lined up beside each other for height adjustments

Little NeoPixel soldiers lining up for me
Photo by chebe



(2) I saw no reason to completely strip the ground rail wire of insulation, instead I just created gaps where I needed to join the NeoPixel spokes.

View of the ground wires of the NeoPixel spokes attached to the ground rail, at base of band, ready to be soldered

Ground rail connections
Photo by chebe



(3) I brought the power wires to a power rail on the inside of the band, the same way I did the ground rail.

View of the power wires of the NeoPixel spokes attached to the power rail, inside the band, soldered up

Inside view of power rail (and data lines) soldered up
Photo by chebe



(4) While soldering things together I realised that my NeoPixels (from PartFusion) have the I/O pins reversed. So I had to flip the side my microcontroller sits on to the right. (He's fixed that in the new version.)

View of right-hand-side of band with Gemma microcontroller attached vertically

Gemma sitting pretty
Photo by chebe



(5) After trying it on this arrangement seemed overly (even comically) asymmetrical. So I flattened the Gemma to sit horizontally. (It should sit comfortably between my scalp and any fancy hair-do.)
(6) Also, as this is an older Gemma without the onboard switch I added one in the power rail to the NeoPixels, so even if I can't switch the microcontroller off I can turn off the LEDs.
(7) I added a wire from the left-most NeoPixels Output pin to nothing, to keep the symmetry.
(The soldering may look messy with pointless joins, that's because I tried to add metal snaps into the circuit so I could move the Gemma around as needed, but I must be rusty, they just wouldn't cooperate.)

View of inside the band, Gemma sitting horizontal, and power rail switch just out of focus

Gemma sitting horizontal
Photo by chebe



(8) And then finally, because no project is complete without it, I covered all the solder points on the rails, and secured the wires going to the Gemma, with hot glue.

View of base of the band, with Gemma sitting horizontal, and hot glue everywhere

The base view no-one will ever see
Photo by chebe



And here it is, running the test code provided in the tutorial, sitting nicely atop my un-done-up head.

Tiara on top of my head, looking nicely symmetrical, with centre NeoPixel lit up

Finally, my royal position secured
Photo by chebe



And, because the tutorial code has a nice sparkle effect to it, here's a short video.



I am going to wear this everywhere.