Automatic cat litter box.

The toilets did fine during testing, so I've made some more, version 2 :)

I have added:

1. a magic3 for the controller, so there is now a touchscreen, settings etc,
   
2. load cells and a hx711 for triggering and for sand level monitoring,
   
3. an VL53L0X for waste drawer level monitoring
   
4. and vibration.
   
   

This last one is very important:

The toilet can now handle pellets, a world's first I believe, it can scoop the solid waste and sift the sawdust at the same time.

This is a game changer, it leads to less waste volume and sand loss, for a fixed available volume it almost doubles the time needed between refiling the ball with sand/emptying the waste drawer.

It also makes the silicone lining most commercial solutions use not needed, when using a clumping sand type like betonite, 5 seconds of vibration is enough for everything to get unstuck.

I will upload a demo during the weekend, but until then if one can guess where the vibration is applied, and how the sawdust exits the ball, I will be happy to read.

ps.
if one cares to think about it mechanically but has no cats and no idea about the pellets+automatic toilets problem, it goes like this:

automatic toilets need a clumping type of sand, so that waste, solid or liquid, can form an object larger than the hole openings. The sand will trap it self and the waste will roll out.

Pellets do not clump when liquid is present, they dissolve to sawdust. This means that the dust will get trapped along with the rest of the sand, it cannot exit the ball, till now :)