Help with my arc reactor!


I’m trying to build an arc reactor chest piece for a burner costume, and while I’m solid when it comes to the prop object build, I’m lacking when it comes to wiring it for light. Ideally it will have two distinct effects- a pulsating ring of blue leds and one dimmable central white one. I can solder but don’t know how to design the circuit. I’m happy to barter with my other skills.


if you are thinking of using a neopixel ring at all, consider getting yourself a partycat board from @lukecyca


I was also going to suggest a Neopixel ring. It might be a little overkill depending on how you are planning to animate the LEDs, but the form factor should suit and it would require minimal soldering. They are also fairly straightforward to control.


added benefit of a partycat is that there is a separate pwm output to control the dimming of the center light if you wish


Use a partycat, it was pretty much designed for this. Get a neopixel ring and get a super bright central white LED. Get one that goes so bright you can actually pretend to use the beam weapon iron man uses in the first one.


I’ll check out the particat… will it also work with a circuit of 10 individual LEDs? The reason for this over a neopixel ring is that when I cast the resin ring for the reactor I specifically made holes for LEDs do that the glow would appear to come from within


RGB LED modules come in a variety of form factors. See

Maybe the 12mm bullet or the 8mm one would work. Either way you’ll have a bunch or wires to connect. A neopixel ring would be a nice tidy single piece.

I still have one or two party cat kits left if you’re interested. See ESP8266 WS2812 “Partycat” controller


You can also get the thru-hole discrete led style in 5mm (look for APA106 5mm) which may better fit your already built ring…
It will require more wiring but be less noticeable…


Well, depends on the LEDs.
Partycat is very much meant to work with one string of ws2812 LEDs (or ones that use the same protocol) and a string of other LEDs, through the mosfet.

So, if you wanna go that route (which I suggest), grab or (8 or 5 mm WS2812 LEDs), and hook them up to the partycat. This will allow you to do a bunch of great patterns on the outside rings.
Then get central LED like this:, or something similar (maybe even brighter if you want to be able to light up a room, or a soccer field)

Don’t necessarily order from adafruit. They aren’t the cheapest, but they do have great quality and customer support.

Lots of people here will be able to help with partycat and programming.

One more thing: Think about an input, like a button, to change patterns. (This CAN be your phone, as the partycat is wifi enabled)
Also think about where you’ll be providing power.


Can I buy one from you tomorrow? I’m free any time before 2:30


Sure, I plan to be at VHS by 1pm.


Thanks to @lukecyca for meeting with me. I’m going to use individual neopixels, as my prop needs very specific spacing. Here’s my wire management design that will keep things neat: