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Or apparently even a month!  This project was the bane of my existence for ages.  Tony Stark is my spirit animal, and I have been itching to make a prop arc reactor for years.  I’d been looking mostly at 3D printed options, but hadn’t found a model I liked enough.  Earlier this summer, I was browsing through Adafruit’s Learn pages and found the perfect model!

It seemed easy enough on the surface.  I’d already done a project with Neopixel rings and a Trinket earlier in the summer, and this seemed like a nice step up to working with a Gemma.  Parts were ordered, and I started planning the build.

Arc Reactor 1

The faceplate for the reactor was the easiest part.  While I was tinkering with the laser at Create, Make, Learn I snagged some blue acrylic and cut both versions of the faceplate (choices are great!).  I was prepared to head home, break into my Adafruit package, and build away.

Arc Reactor 2

Initially, the build went well.  The Gemma isn’t too different from  a Trinket, and I felt pretty confident working with it.  The problems started when I started looking at the circuit diagrams.  First I followed the graphical circuit diagram.  After ages hunched over the soldering iron, I tested it out, and……nada.  Nothing worked.  Ugh.  Time to de-solder.  Second time around, I followed the photographs of the wiring (which were different than the graphical diagram!).  An hour or so later, still nada.  By that point, I was super frustrated and needed to step away from the project for a bit.

I decided to go back to what I was familiar with, and try the project with a Trinket instead of a Gemma.  Ordered a couple of Trinkets, and a few extra Neopixel rings, and waited for my order.  When it arrived, I had a facepalm moment when I realized I had forgotten to order the JST battery connectors for the Trinkets.  UGH.  Another Adafruit order, and waiting for it to arrive.

soldering workspace

Finally, all the parts were in one spot, and I was ready to try again.  This time I followed the basic wiring from the Neopixel goggles I had made previously.  Everything went smoothly until it was time to add the code.  I was working in Arduino, which I have a little bit of familiarity with.  Technically, I should have been able to just copy and paste to project code from Adafruit, transfer it to the Trinket, and have a working arc reactor.  In reality, I hit another wall.  For some reason, my Arduino app just could not connect to the Trinket.  I couldn’t even get the bootloader to work.  Once again, I had to step away from it for a bit.

When I finally came back to it, I decided to leave the Arduino code alone, and try the CircuitPython code instead.  This took some more trial and error, but I was finally able to get some proof of life from my project with a default Neopixel test code.  FINALLY!  I was still unable to get the project code working, but once I knew it COULD work, I started tinkering in Python.  Keeping it simple, I was able to get the Neopixels to all light up solid blue.  Step one complete.  Next, I tinkered some more and was able to get them to change to a lower brightness.  Huzzah!  All that was left was to loop the code so it would phase between brightnesses.  Success!!!

It’s far from finished….the brightness loop works, but is a sharp delineation between light levels.  Now I want to figure out how to have the brightness fade smoothly in and out.  Thankfully, I have several friends willing to help with this part at Maker Faire this weekend.

As far as physical finishing touches, I used good old E6000 glue to attach the Neopixel ring to the faceplate, added an extension wire and on/off button to the battery, and attached a necklace loop to the back of the faceplate.  With the addition of a necklace chain, it now sits perfectly under a shirt.  Next up, make the second arc reactor with the older version of the faceplate, and then wait for the Neopixel strips to be back in stock so I can move on to LIGHTSABERS!