Stopping dog from eating cat poop (with engineering)

Does your home have any pet doors or gates for dogs, cats, or other animals? Some automatic pet doors can be set up to allow only certain animals through. These doors can help you control which pets are able to go outside alone or which ones have access to specific food, litter boxes, or toys. But why buy such a door when you can make one? In this project you will build your own automatic pet door that works with a magnetic collar tag. Exactly how you use it is up to you! Read more