We did some brainstorming today on how to implement the sensor that would allow the door to act like a one-way valve, essentially allowing the dog to enter but not exit the house. To do this we need to detect when a dog comes close to the door, open the door and wait until the dog is no longer present before closing the door.
We came up with a couple ideas that each have their pros and cons:
We also talked about the physical layout and mounting of the whole assembly. The following diagram shows a base plate that all electronics are mounted to, and a cover to go over everything and make the door look clean. The base plate and cover will have mounting holes to make everything easy to install. A hole through the door might be necessary for wires on the opposite side.
We came up with a couple ideas that each have their pros and cons:
- PIR range sensor
- Pros: Cheap, easy integration (high-low signal), nonintrusive
- Cons: Not great in outdoor environments
- Ultrasonic range finder
- Pros: Better for outdoor use, non-intrusive
- Cons: Narrow field of view, slightly more expensive
- Load cell (bathroom scale)
- Pros: Can weigh dog to identify
- Cons: Intrusive
- Spring-loaded button/FSR/Pressure sensitive platform
- Pros: Easy, Cheap
- Cons: Intrusive, not failsafe
We also talked about the physical layout and mounting of the whole assembly. The following diagram shows a base plate that all electronics are mounted to, and a cover to go over everything and make the door look clean. The base plate and cover will have mounting holes to make everything easy to install. A hole through the door might be necessary for wires on the opposite side.