I'm rather new at home automation. I'd be interested in feedback regarding a plan for a passive entry system to my home. The plan and components I have envisioned exist but I have not seen them configured in the way I've planned.
Pictures from the top, inside, and outside of my front door can be found at the following urls (I apologize in advance for the smallness of the jpg's that msn groups pulled from my computer -- hopefully my description below will provide the detail that may be so small as to be illegible on the jpgs):
Top View
Would anyone like to comment on applying a long range proximity reader to home automation application?
Since the long range proximity readers I've come across are on the order of 12" x 12" or larger my thought is to mount it indoors (in the drywall??) where it is not an eyesore. Should I reasonably expect this sort of installation to work? Are there challenges with this sort of installation that I need to be aware of?
With a long range proximity reader I need to be concerned with the distance that the reader penetrates indoors (I have provided for this in my diagram by specifying that the read area extends only outside the front door). I don't want to be activating my front door once I'm inside. Are proximity readers typically directional? Can they be made directional by the use of properly placed shielding? (metal??)
(2) Keypad mounted outside - I've seen some keypads (some elegant, some ugly) on the web (feel free to make suggestions if you would). They keypad would provide access in lieu of a keycard (for house cleaners, guests, etc.) allowing me to add/remove access codes and limit access to specific times.
(3) Control unit mounted inside - Don't know if this is the proper term but I understand that separating this from the keypad is a more secure solution.
(4) Electric strike - Would be activated by either proximity reader or keypad via control unit. I like the fact that the electric strike is mounted in the door frame and is therefore capable of being powered without having to wire the door itself.
My expectation is that the strike, when activated, would allow the door to swing open for some preset time. I'm wondering about how much time I should alot. I suspect it's easier with a short range proximity reader as one expects that entering the door is immediate upon activation. I don't want the door to prematurely "lock" so it should be longer than 1 second delay. On the other hand, I don't want the door to swing open for 10s of seconds after entry so the delay should be shorter than 30 seconds. Is this going to be a pain in the butt?
(5) RF electric deadbolt - I would love to have a deadbolt which functions in the same way as the electric strike. Since a deadbolt isn't a latch and since a deadbolt isn't spring activated it appears an electric strike won't work with a deadbolt. That leaves an RF deadbolt with a key fob as an additional component to the plan. The idea of replacing batteries for the thing seems rather inelegant to me. My father-in-law suggested a second latch acting as a deadbolt (with a second electric strike), IF there exist latches which act (and look -- who wants two doorknobs on a door) like deadbolts. Does this beast exist? Would this be as secure as a deadbolt?
(6) Fail secure - Both the deadbolt and the electric strike would be fail secure. I would have both keyed on the outside and a handle/knob on the inside in case of power failure.
Please feel free to comment on any or all parts of the plan. What am I overlooking or failing to appreciate? What should be I looking for from these components if I was interested in hooking this into a comprehensive home automation system?
Thanks for your patience in reading this rather long post.
= Joseph