Door locking monitor

[computer]

Hi,

Quick question, but I have a PVC door at the end of a long corridor on my house and I'd like a beeper by my front door to beep if its unlocked when I open the frontdoor. This bit is fine, I have CAT5 links at both ends I can join up and some pics I can use to monitor etc, but I would like a little help on if it is possible to check if the pvc door is locked or not.

It has like double locking, with little top bolts that go up into the frame when its locked. I was wondering if it was possible to use some sort of sensor I can fit on the frame to detect the metal spike bolts or I have heard it mighht be possible to use some sort of hall detector or magnetism circuit.

Any ideas? I don't want to have to cut into the door, but possibly I can cut into the door frame.

Computer

 

[zachtheterrible]

ive never messed around with hall detectors yet, but i think that if you have a magnet and the hall detector within like an inch of each other, the hall detector will detect a decrease in magnetism when the bolt is slid close to the magnet hall detector combo, and an increase when it is slid away from the combo. Thats the way i would imagine it should work :lol:

Or you could just have a magnet on the end of the bolt, thats probly simpler, but you'd have to shorten the bolt in order for it to fit.

 

[dingo]

I don’t think hall detectors will work too well here. Also don’t like the reed switch due to the size of the magnet needed for it to work reliably would be a little hard to glue to the bolt.

I can see a few different options

Micro switch either on door showing it unlocked or in the hole the bolt goes into showing the door locked.

IR led and detector, same idea as micro switch just no moving parts and is smaller.

Proximity detector, this is a glorified metal detector used in industrial applications. Anything metal within a few centimetres will switch it. Problem is that they are the size of a matchbox and not that cheap to buy also if the frame is metal it will not work too well.

Place a spring in the hole. Join a wire to the spring, another to the bolt so when the door is locked, the bolt closes on the spring, you complete the circuit. You could even join a wire from bolt to bolt then so both bolts have to be in to complete the circuit on the spring in either hole.

 

[plot]

if it has a deadbolt with a nice big latch you turn sideways to unlock the door or upright to lock the door (like shown here: **broken link removed**), you could set up an ir detector so it doesn't hit the thing when it's locked, and nails it sqaurly when it isn't locked... or visa versa... depends on how the doors is settup really i guess.

 

[zachtheterrible]

like i said, i dont have a clue about magnets n hall detectors (i was just guessing). wut about those alarms that beep if a door is closed or opened? could this somehow be applied?

 

[dingo]

like i said, i dont have a clue about magnets n hall detectors (i was just guessing). wut about those alarms that beep if a door is closed or opened? could this somehow be applied?

Not if you want to know if the door is locked or not even if closed. You have to know if the bolt is in or out. This means a sensor or switch of some kind on the bolt.