Hard Drive Platter Mood Light: First Light!

Disassembling the (unglued!) platter stack simplified wiring the the Neopixels:

Hard Drive Mood Light - test light
Hard Drive Mood Light – test light

Orienting the strips in alternate directions kept the white data connections between adjacent strips on the top and bottom level. If they sat in the same direction, the data wires would run from top to bottom.

Each Neopixel draw 60 mA max, so each side of the pillar can draw 180 mA and lighting up all four sides in full-throttle white draws a bit over 720 mA. That’s more than those little Wire-Wrap wires should be forced to carry, but the tiny Neopixel solder pads aren’t good for much more than that. The revised column model has wiring channels behind both strip ends to provide access to the slightly larger pads on the rear surface; the fact that all the end pads get cut in half doesn’t help matters.

The red and blue power wires connect adjacent strips, with two opposite strips wired in parallel at the bottom of the column. There’s a 100 µF cap across the incoming power leads: as much capacitor as would fit in the somewhat undersized base.

A knockoff Arduino Pro Mini sits inline between a 5.2 VDC wall wart and the Mood Light with three connections: VCC, GND, and D6. It’s flapping around in mid-air with no protection whatsoever, so I’ll let your imagination draw that picture. I want to hide it in the base, along with a power jack, as part of the fine tuning.

Anyhow, restacking the platters produced this pleasant effect:

Hard Drive Mood Light - low angle
Hard Drive Mood Light – low angle

You’re seeing each LEDs both directly and through a reflection in the platter below it. Despite having handled the platters for a few days, the reflection’s clarity surprised me; the multiple reflections required to bounce the LED image to the edge of the platter work perfectly:

Hard Drive Mood Light - high angle
Hard Drive Mood Light – high angle

Running the original firmware (which, as noted in the comments, will eventually fall off its rails), the colors change slowly enough to be always the same while you’re watching and always different after you look away:

Hard Drive Mood Light - red
Hard Drive Mood Light – red

The platters stack sufficiently parallel to each other that the LED images still have the right spacing after multiple reflections. It’s not quite an infinite house of mirrors.

With the LEDs running at half intensity (PWM limited to 128/255), the stack lights up a dark living room just fine. At full throttle, it’d probably be too bright…

All in all, it looks suprisingly good!

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