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.
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.
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.
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!