Have you tested all of your NeoPixel strips at this point? Because I swear I will turn this car around.

Start placing your drips, securing them in place with hot glue, Krazy Glue®, zip ties or whatever your install calls for. Some wires here simply fit through the eye or nose openings, while others I drilled small holes through the skull.

The number labels were moved to the data wire for each strip. Must keep track of those!

Don’t worry if the strips hang outward at weird angles…just get them attached and straighten them out afterward.

Also: DON’T BE LIKE ME. I glued down all the “splats” before the drips, based on my earlier estimates of their positions. Much better to install the drips first, see where things actually hang at that point, and then glue down the splats, fine-tuning their positions as needed! Mine are a bit off.

You’ve been grappling and rough-handling these NeoPixel strips…so, I’m sorry, but it’s a really good idea to test them all again and fix any problems now, when they’re still accessible.

Did you test everything again? Okay good…

Down the middle of the NeoPXL8 board is an 8x2 header. One row of this are the NeoPixel data outputs, the others are grounds. For this project we’ll be soldering only to the NeoPixel outputs (with the numbers just above them), not the ground points (with “–” below). Plus of course the USB and GND wires mention earlier, to the power bus.

Starting to make connections from the first two NeoPixel strips to the NeoPXL8 FeatherWing and my makeshift power bus.

As a sanity-preserving measure, I had simply soldered identical foot-long wires onto every strip rather than measuring out each one ahead of time. Now at this stage I clip off a couple inches, whatever’s actually needed to reach from point to point, with a little slack so I can still move things around while working on this. Wastes a little wire but saves a lot of time.

Keen-eyed readers might spot there’s two data wires going to NeoPXL8 outputs #0 and #1. Yours might not need that…it’s something covered on the Extra Drips page.

Soldering wires directly from the top skull to the base was just asking for trouble…I knew there would be a lot of wrestling parts into place here.

I added a 3-pin JST SH plug and receptacle so the two parts could be separated while working on them. This turned out to be really helpful during assembly (I could plug that in later as a next-to-last step), but also just in case I needed to go back inside for maintenance. Strongly recommend this for your splat pixels!

All power and data wires connected, including the JST plug for the splat pixels.

An important step…not shown here…was to load up the NeoPXL8 strandtest example and sort out the correct pinout for the board we’re using as explained in the NeoPXL8 guide…sometimes the FeatherWing needs some traces cut and jumpered, and this is the last time you’ll have easy access to the board.

With the basic NeoPXL8 test sorted out, load up this project’s OozeMaster3000 Arduino sketch, copy over the pin array you worked out for strandtest, and test it all again. Even if not using the final settings, just making sure there’s no shorts or bad pixels. The code is explained on the next page. Later we’ll make further tweaks for the actual strand lengths.

After it all checked out, I glopped up these wires with hot glue to provide some strain relief when this gets stuffed into the skull, and similarly covered the back side of the power bus to prevent it shorting on other parts.

Since the Feather board will be buried inside this skull, I connected a micro USB cable and hot-glued it in place so it won’t fall out, then fed the other end out an opening at the back of the skull.

If you do this, make absolutely certain it’s a USB charge and sync cable, not a charge-only cable! Please test this first. A charge-only cable can provide power but won’t let you update the software on the board.

Wiring’s done, sealing up the skull. You can just make out the hot-glued USB cable here.

And yes, test it all again.

The NeoPixel strips running along the skull are pretty conspicuous, so I camouflaged them with some cheap craft store acrylic paint.

Don’t sweat it if your painting is sloppy or colors don’t match. Five feet away, nobody will notice.

If you get paint over any of the NeoPixels, it can be scraped away with a toothpick, or a Q-Tip® dipped in rubbing alcohol.

To conceal the wires inside the skull, I stuffed some wads of black chiffon that I found in my crafting hoard.

As a last step, I cut a circular skirt from thin fabric and placed this over the base. It hides the “splat” electronics while still letting enough light through to complete the illusion…you can see this in the project’s title image.

This guide was first published on Oct 23, 2019. It was last updated on Mar 04, 2024.

This page (Build Part 2) was last updated on Oct 23, 2019.

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