By Ben Everard. Posted

Let’s be honest: these are for one thing, and one thing only – Halloween. There are two 240×240 pixel SPI screens connected to a SAMD51 ARM M4F microcontroller. There are also three buttons if you want to trigger different effects, and an audio jack for sound output.

You’ll almost certainly want to use this on the go, so there’s a LiPo battery port and charging circuit.

In their most basic use, you just plug the power in, wait a few seconds, and they’re on and looking around. There are four mounting holes positioned, so it’s easy to tie (or zip-tie) these onto costumes, if it’s not appropriate to bolt them on. These can also be used to hold on a pair of hemispherical lenses (sold separately) to give these a more eye-like look, particularly if you mount them inside some other make – imagine these eyes poking out through a piece of clothing or a prop.

The quality of the screen and animation is stunningly good. The original name for this eye animation (when it was first coded by Phil Burgess to work on the Teensy) was Uncanny Eyes, and they really are uncanny. For us, it’s the animation rather than the realism of the image (though this is also impressive) that gives real personality.

There’s plenty you can customise about the eyes, and there’s a detailed guide for doing this here. You can do much of the customisation without getting your hands dirty with programming – the device shows up as a USB disk when plugged into a computer via USB, and you can tweak configurations and image textures without having to recompile.

There's enough connectivity to add quite a bit of extra hardware to your Halloween costume, and power it from your MONSTER M4SK

The mask is designed so the eyes are the same distance apart as on the average human, but if you want more or less, you can detach the two halves of the PCB (see the dotted lines around the nose? Those snap).

This obviously breaks the electrical connection between the two halves of the PCB, but there’s a solderable nine-pin JST SH connection. As there’s lots of data flowing through this, it can’t be extended arbitrarily as electrical interference will distort the signal – around 10 cm should be fine, but longer than that and you might find you have problems.

If you need more input or output, there are two three-pin STEMMA connectors, one four- pin I2C STEMMA, and a JST connector of a PDM microphone.


There’s no getting around the fact that the code to perform this eye animation is complex, but it is well structured and commented, so worth a read through if you’re interested in what’s going on. You’ll find it here.

This is also a good starting place if you want to use this board for something different. Obviously, a lot of it is very eye-specific, but you’ll also find all the details of how to connect to all the on- board hardware.

As the board is fully hackable, you don’t have to use it for eyes. You could use it for any project that needs two square screens. Flip them around, add lenses and you’ve got a DIY VR setup; they could be a screen each for a two-player game; or they could be simply two screens for outputting diagnostic information. Look beyond the eyes and it’s a powerful, programmable microcontroller that you can use just as you would any other microcontroller.

These TFT screens emit light, so work brilliantly in darkened rooms

In a world where landfill is full of obsolete gadgets, it’s important to be able to reprogram and reuse your technology. However, despite the repurposability, there’s no getting away from the fact that these are designed to be animated eyes. There’s something fundamentally endearing about hardware that’s well engineered to do a single job – especially when that job is to make people smile.

We’ve looked through the technical specs, and how to use it, and how it could be used in the future, but all these are largely irrelevant. What matters with this hardware is how it makes you feel, and it makes us happy.

We’re used to being surrounded by high-definition screens covered in all manner of images and details, but these are different. Perhaps it’s because the form factor is so unusual. Perhaps it’s because in eyes we see humanity in each other, and therefore with these, we see humanity in a machine. Perhaps it’s because sufficiently advanced magic is indistinguishable from technology and these are magic. Whatever it is, it’s one of the most fun gadgets we’ve tested.

Verdict: 10 out of 10

An easy and fun way to add ‘wow’ to your Halloween costumes.


From HackSpace magazine store


Subscribe to our newsletter