The outer shell of Cuboid Cat is a 3D printed cuboid made from semi-transparent filament. Housed inside is another cuboid made with alternating layers of black and white filament.

Facing forward are three compartments housing LEDs. Switching LED on/off has the effect of opening the eyes or mouth.  

On future prototypes the PCB will have two photoresistors facing upwards for detecting human interaction. 

Other components I plan to use are a ATtiny85, a cellphone vibrator motor, a piezo mic and a speaker.

Behaviour

Here's the outline for how Cuboid Cat is supposed to respond to interaction: 

• Stroking CCs back will block light to the photoresistors in sequence, resulting in purring and vibration.
• CC will respond to sound by meowing and/or blinking eyes. Preferably it would mostly respond to human voices.
• CC will respond to sudden changes in ambient light (turning the light switch).
• CCs eyes appears to always be looking straight at you. This is a passive perspective effect achieved by the eye LEDs being mounted in internal compartments.

When will I come up with a functional prototype?

Not sure. 

I made this dumb prototype a few years ago but I got distracted by something else and forgot all about it. I recently found it in my (crammed) drawer of unfinished projects and felt that it's a pretty neat concept and that I probably should finish it at some point. 

The project will probably be idle for some time yet before I can start putting any hours into it.