I'm new to the world of build your own electronics so I hope this isn't a terrible question. A while back I built an automatic dog feeder with a simple timer and DC motor. The hopper is so large I only need to fill it every two months or so and the last two times I didn't realize it was low on food until it was empty. I want to make an indicator to show when it is getting low so my poor pup wont be without food for a day. Here is a diagram of my Idea and I was hoping I could get some thoughts on if it will work or perhaps a better way to do it. The basic concept is to have In IR LED in the top of the hopper and an IR phototransitor that would be uncovered when the food level got too low and change a status LED (green for food, red for empty).