How can I build a pet door that opens with magnet/radio collars?
Secondary (less important) question : How can I make two pet doors that open this way, but only one collar opens one door?
I need to create a three way split in my house, [ A | B | C ] one cat can access part A but not part C. One cat can access part C but not A. Both can access part B.
I would like to create two pet doors that open by sensing magnets or radio frequencies that can be attached to their collars.