Does any one know how to rig a reed switch to a bluetooth device to notify you if someone has opened a door or not?

im looking to see if anyone knows a way to rig a bluetooth usb drive or something to a reed switch to automatically connect to your cellphone when the reed switch is activated?

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Taost7 years ago
Arduino with bluetooth shield, you'll need to figure out the programming though. >.>
maxs7 years ago
I don't know your exact setup, but you could use an ioBridge to bridge the reed switch to the Internet (text message, web site, twitter, etc.).

Take a look at  You could connect the reed switch and the Internet (cat5 cable) to the ioBridge board.  Then when the reed switch opened or closed (depending on which kind you used), it could text message, tweet, update a website (for timestamp history).
mpmansell7 years ago
 The problem with using a USB BT device is that it needs a computer to function. So, the simple answer is to use a computer with a BT dongle and an I/O card/dongle that is attached to the reed switch.

I am assuming that this is not what you really want to do, otherwise I assume you would have done so already.

What I suggest is that you look at using a microcontroller with a BT module. Something like a 16F series PIC would be cheap and relatively straightforward to both program and interface and code to communicate with the BT module is probably already available as an API. It is also possible that a MCU  module already exists with BT built in.

Unfortunately, though, while a USB BT dongle can be bought for just a couple of quid, it is unlikely that the final solution would  be anything near as cheap.
Trecko12347 years ago
I know a way to check if anyone has been in a room . Put a half of a matchstick in between an open door and the frame. Then close the door and break of the half. If anyone went in, the match would be on the floor.
JoshRidlon (author)  Trecko12347 years ago
by that time the boss has allready busted you
Well a BT mouse might do it. Then you'll have to write code to run on the phone. The range isn't going to be great either.


JoshRidlon (author)  steveastrouk7 years ago
I was thinking a BT usb would work because some have a distance of 100m but i dont know how to rig it to turn on when the reed switch is tripped
You could get a second phone on one of those cheap "only pay when you use it" plans and leave it near the bluetooth device to eliminate the range issue. The second phone could send a text to the primary phone.

Might be overcomplicating the issue, though.
....given the actual range of a BT connection, you'd be as well off with a bit of wire and a good loud buzzer.....
Or to really overcomplicate matters, skip the BT altogether and have it tweet the updates to the phone. I mean, if you can make an office chair tweet when somebody farts....
 maybe you could get an old phone, plug it in to a charger and have a message ready to be sent, when the door opens you could have a reed switch or something hooked up to the send key.