DIY Digital Scale as a Sensor?

Problem: Fat cat has access to skinny cat’s food, and will eat it all.
Previous Solution: Move bowl there. Move bowl back. Move bowl there. Move bowl back. Close door, open door, close door, open door.

Compound Problem: Forget to move bowl --> Fat cat eats food. Forget to close door --> fat cat eats food.

Goal: Grant access to food, but only to skinny cat.


  • Some sort of RF device on their collar that triggers when they’re near the bowl.
  • A pressure sensitive mat or scale that they stand on while eating that would trigger access.
  • Access via stepper motor, pullies, and cables.
  • Access via sliding cover.
  • Access via hinged lid and lever with servo control.

Anyone out there have any bright ideas and hardware suggestions?

If you don’t want to DIY:

Although it wouldn’t be nearly as fun to tinker with something like this, it would solve the problem immediately.

Well, there’s always the load cell option? Take a look at for that. may be of some interest with possible problems.