19th Ave New York, NY 95822, USA

Grenade Lights and Sound Test

I’ve made a bit of progress on the Arc Grenade that I’d like to share, so let me catch up with a couple of pictures and videos. None of this wiring was hard, it was just tedious. The idea was that it would be able to transition from an active-but-idle state to an ‘armed’ state, which begins a windup animation during which you’re ostensibly supposed to throw the thing the hell away from you. Once the ‘explosion’ is done, it returns to the idle state. None of this wiring was hard, it was just tedious.

My test board. Each Neopixel (or, well, in this case, they’re non-neopixel ws2812 LEDs, but they work the same) has its own .1uF capacitor between the +5v line and ground. This is apparently recommended for these things to alleviate any irregularities associated with the funky data signals required to have individually addressable LEDs. I won’t pretend to know or understand how it works – I only follow directions!

With that said, each of the 18 LEDs had its own .1uF capacitor ‘backpack’ soldered on:

Then we get into the wonderfully banal process of attaching a million zillion wires to each leg.

Each LED assembly needed, at minimum, three wires. The data in from one connects to the data out from the LED before it; the +5V and Ground lines (red and black) are carried between the middle pins to the subsequent LEDs down the chain. I soldered everything together and wrapped them in heat shrink to ensure there was no chance of the wires touching inappropriately…

… and ended up with about a meter of christmas-light-esque LEDs. Make sure you test as you go! You don’t want to find out late in the game that something isn’t contacting properly.

The last bit is tucking all this wiring inside the body of the grenade itself. I set the LEDs up in a spiraling pattern around the inside of the cavity.

Each LED is pulled through the hole, superglued into the arc plug, then the arc plug is superglued into the body, and hot glue is used to fill the empty space to keep the wires from wiggling or getting pulled out later. It’d be a nightmare if an LED came loose in there once the grenade is totally sealed up!

A video of the test assembly:

Leave a comment