This is for identity only, with a key and alarm code out of hours. We've
got the bias set firmly towards identity and tracking rather than
security, security will be covered by other means.
I'm planning on securing a pi in the roof void above each door with a
cable down to the reader and mag release. these will each use some kind
of replication (undecided what yet, possibly flat files pushed with
ansible) for configuration and asynchronously log activity back to a DB
somewhere over network. They will all be on fail-open so UPS is not a
concern, though we did consider a UPS'd ring for them. Maybe later :)
Do you have recommendations other than HID? I would like to use Mifare
as the tags are cheap and there is a good variety of options for form
factors.