Well that was quick. On the werewolf Teardown page, I predicted this tech would eventually find its way into inexpensive decor and masks. But just two years to trickle down to sub-$20 items is a bit of surprise!

This Digi-Eyes Mask (Party City, Walmart, etc.) retails for $16.97 + tax, and that’s including a set of AAA batteries that are already flat and leaking.

Like the famous Home Depot Giant Skeleton, this plastic skull mask has my roommate’s eyes staring back at me, so we already know there’s some technological DNA in common with the prior products.

Also like the big LifeEyes™ props, the mask’s eyes follow a repeating, fixed path and the pupil dilation is simplistic. One difference here is that the mask never blinks (pity…even if they didn’t want to animate this, simply toggling the backlight can make for a passable blink). Though…one could easily argue it’s just that skeletons have no eyelids.

I already have some theories what’s going on, but let’s peek inside…

A quick look inside the battery box first, because I was intrigued by the speaker grille. Does this make noise? It does not. Most likely, a generic box is being used across many products. The tooling for molds is astoundingly expensive, so it makes sense to use the same box everywhere, whether or not a particular item includes a speaker. Cheaper by the dozen million.

A small PCB holds the power switch, connectors and an unmarked 8-pin IC: almost certainly a 555 timer for the “Try me!” feature.

Three screws join the mask and “eye box,” which incorporates forehead support and the bridge of the nose.

Easily moved to another mask or prop if desired, or pop into Jack o’ lantern…if that’s not already a product from the same company.

Familiar guts inside the eye box, at first glance appears identical the werewolf: driver board, ribbon cable and two budget low-contrast color LCDs. The screens are rectangular (160x128 pixels), but “stenciled” through round cutouts in the enclosure.

This board too uses a mysterious “Jerry” microcontroller. But it’s not identical. You’ll notice there’s no flash chip this time, knocking about 30 cents off the bill of materials. On the LifeEyes™ props, the whole eye animation cycle was pre-rendered in that flash chip. Without the chip, what’s up?

I couldn’t locate this exact JLT chip in the current lineup, but from other products there we might infer a reasonable amount of program flash space, perhaps 256K. Not enough for a whole animation as with the Winbond flash chip, but sufficient for a single large image alongside the code.

Thus…between the limited flash and the observed path of the eye animation, we can infer that this new “budget eyes” board is simply doing a pan-and-scan around a larger image, and relying on the round cutout to provide a stencil.

This is quite similar to what we’re doing in the classic HalloWing M0 Eye and Spirit Board projects. The screen and microcontroller are a bit different, but it’s the same pan-and-scan principle. Only significant change is that these projects perform the stencil effect in code rather than with plastic. That’s also why HalloWing can blink, but the skull mask will win every staring contest.

The back of the PCB has “DP” and “DM” pads that might work for USB flashing or debugging…but without publicly-available chip documentation or toolchain, there’s unfortunately zero hacking potential here other than repurposing the whole eye box inside something else. It’s just one step away from an “epoxy blob” circuit. Not that they owe us those things, but it’s always neat when it does happen.

This guide was first published on Aug 18, 2020. It was last updated on Mar 08, 2024.

This page (UPDATE: Digi-Eyes Mask) was last updated on Mar 08, 2024.

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