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.
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.