Automatic Cat Feeder

From Professr's Lair

Problem

Our two cats were eating too much. If we fed them once or twice a day, they would scarf down their food so fast that they'd throw it right back up (stupid animals).

Solution

Build a computerized feeder to dispense tiny amounts of food very often over a 24-hour period.

The main hardware is a gravity-based dog feeder from Petco. I cut out holes to allow a 1-inch PVC pipe to fit snugly between the hopper and the feed ramp, blocking the flow of cat food. Then, I cut a slot in the PVC pipe so a small amount of food would fall into it and then fall down the ramp every time the pipe was turned a full revolution. To turn the pipe, I drilled a hole slightly smaller than a philips screwdriver bit in the pipe's end cap. Then, I smashed a screwdriver bit into it with a hammer, and connected the other end of the bit to a cordless screwdriver. I put together a small PicAxe circuit that pulses a relay once every hour, dispensing about 1/20th cup of food each time.

The cats have learned the sound it makes, and run to see who gets to the bowl fastest - it's a spectator sport.