Yeah, it would be interesting to get an update on FloweringElbow's implementation to see how often the lower limit switch is getting fowled :p .
I think it's also possible to design it such that both upper and lower limit switches are placed higher up on the edge of the door, rather than strictly at the top and bottom, which should help with the fouling.
Practically though, any automated system will be vulnerable to fouling/blockage and require regular maintenance to keep the mechanism clear and clean enough to avoid premature corrosion (chicken poop being pretty acidic). In my opinion, it's a pipe dream to have a fully automated coop in a backyard setting and not eventually/occasionally have failures that require manual intervention or lead to neglect and losses due to predation. Better to think of such systems as tools to relax the timing requirements for manual care. Instead of doing all the work at the right times, one can confirm that the animals are out/fed/watered/in/etc as part of doing the normal morning/evening rounds/chores.
1. Check time and determine desired state (open or closed)
2. Compare desired state against limit switches and run motor until the limit switch is hit (or it times out which is an error)
On the other hand, a turn-counting strategy can lose power in the middle of opening or closing and "forget" where it is in the process.
Their email service - Private Email - (which is otherwise pretty decent) also has a similar issue where they support 2FA and application passwords for the web interface, but don't enforce those rules via the IMAP/SMTP/POP/etc APIs - https://twitter.com/symbioquine/status/1362907237048479745
I think it's also possible to design it such that both upper and lower limit switches are placed higher up on the edge of the door, rather than strictly at the top and bottom, which should help with the fouling.
Practically though, any automated system will be vulnerable to fouling/blockage and require regular maintenance to keep the mechanism clear and clean enough to avoid premature corrosion (chicken poop being pretty acidic). In my opinion, it's a pipe dream to have a fully automated coop in a backyard setting and not eventually/occasionally have failures that require manual intervention or lead to neglect and losses due to predation. Better to think of such systems as tools to relax the timing requirements for manual care. Instead of doing all the work at the right times, one can confirm that the animals are out/fed/watered/in/etc as part of doing the normal morning/evening rounds/chores.