fish feeder mechanism

So far most of the fish feeders i have seen simply dump their contents when told, or are some kind of multi-compartment variation of that. Cool and all, except it is limited to one (or however many compartments+switches or compartments+stages) it has.

I would like to feed 3-5 pellets, from a hopper, for much much longer term usage. The best Ideas i have had are 1. some kind of spinning plastic ring that lets one pellet thru each rotation, or 2. pumper/solenoid mechanism that lets a small cluster drop into a compartment, then pushes the contents out in one go.

for the spinner, I envisioned using some kind of medicine bottle top - the anti-tamper ones with a rotation sub ring, and punching a hole between the two. I have not been able to get it right yet, maybe I need to get some more medicine bottles to try. For the solenoid style, I was thinking about a straw, with a solid slider inside it, then fashion out a hole large enough for the desired number of food pellets. I have not tried it yet, but it also seems difficult to construct.

Do you think one of these options best, or have another idea?

Thanks!

This feeder uses the lets-some-through-every-rotation method. It's not an uncommon design; you should be able to find some videos of them in action if the mechanism isn't obvious.

http://www.amazon.com/Cambridge-Aquatics-Automatic-Fish-Feeder/dp/B001MUPHGY