I am trying to build a simple rice dispenser (actually rice, beans and so on). I've seen a few arduino automated cat/dog foods dispenser around. I have no 3d printer at hand so what do you suggest me?
It's my first attempt so there is no need to be perfect.
I though about the cylindrical recipient with a hole on it, which is rotated by a servo. When the hole is downwards, it will let a few grains out of it (it would be perfect it it was just a single grain). I can probably implement this one on my own right now (just a single servo, and that's it?), but it's quantity will be affected by the amount of grains available inside it.
The other approach that I saw was to have a box with a hole on the bottom which is open to a smaller recipient. The smaller recipient is thus filled by default. When we want the rice, we can push the smaller recipient, which would then block the opening of the larger recipient and at the same time eject the smaller recipient's content since there would be no bottom support when the smaller one is moved. In this approach, I don't know how to make a servo push/pull a box (any links?)
I also saw the approach from this guy: http://www.instructables.com/id/Arduino-controled-dog-foodtreat-dispenser/ I don't know if it's possible to build a really smaller recipient version of it and if it wouldn't spill a lot of its content (we can see some spilling in the video).
I will probably try all of them, but any hints are appreciated.