I have a 3' (1 meter) tall plastic gate around my yard. I would like to automatically close it with my Arduino or Raspberry Pi. Not by remote control - I just want it to detect that the gate is open, wait a few seconds, then close it.
I figure I need 2 things:
- A sensor to let the Arduino know if the gate is open or closed
- A mechanism whereby the Arduino can close the gate.
I feel good about my ability to find and implement #1, but I'm not at all sure about #2.
The gates curently use this kind of latch:
I figure to force-close it the mechanism would need a fair amount of force (I'm not sure how to measure or quantify this). OTOH to close it by first pulling back the latch, then pushing it closed and releasing latch seems like it would be much more complicated (?).
I'm also open to some different sort of latch to work with the robotic closer. Maybe some magnetic latch would work, but it would have to be strong enough to keep my 25lb Sheltie dog from opening it.