Well, for my latest chicken house door project, I didn't want to bother with external limit switches and the necessary wiring.
So I mounted the motor on a kind of see-saw plate with springs and micro-switches so that the when the door gets to to the bottom and the line goes slack, the door stops. Also means it stops if it meets an obstruction (a chicken, for example).
On opening, when the door gets to the top it meets a physical stop, the line goes taut and the motor stops. Also means if the door is jammed - like on a frosty morning, the motor does not burn out.
Both the limit switches and the motor are in a waterproof box with no external wiring.
The motor has a worm drive so the tension remains when the motor switches off.
It's been working for at least 3 years now - no probs!
The picture shows the motor with the door open. So the heavy spring is fully compressed. The cord goes out horizontally left. Outside the box it goes over a pulley down to the door.

 

Well, for my latest chicken house door project, I didn't want to bother with external limit switches and the necessary wiring.
So I mounted the motor on a kind of see-saw plate with springs and micro-switches so that the when the door gets to to the bottom and the line goes slack, the door stops. Also means it stops if it meets an obstruction (a chicken, for example).
On opening, when the door gets to the top it meets a physical stop, the line goes taut and the motor stops. Also means if the door is jammed - like on a frosty morning, the motor does not burn out.
Both the limit switches and the motor are in a waterproof box with no external wiring.
The motor has a worm drive so the tension remains when the motor switches off.
It's been working for at least 3 years now - no probs!
The picture shows the motor with the door open. So the heavy spring is fully compressed. The cord goes out horizontally left. Outside the box it goes over a pulley down to the door.

Clever mechanism.

 

The first sign of Spring on an electronics forum - the emergence of chicken coop door threads.

ak

 

Is there a minimum acceptable (non-zero) gap when the door is closed? If so, that could the height for a limit switch to start a timer, and all the way down is the place for the fully-closed switch. If that one does not close before the timer times out, the timer removes power from the motor.

Since you can control this with your phone, can the system send you a message?

ak