Doorway proximity detectors

[Andrew Millne]

Is anybody using ultrasonic/optical doorway proximity detectors in addition to reed switches for presence detection? If so can anybody recommend any specific detectors they are using?

Thanks

[toscal]

I've used multiple beam sensors at door ways to detect intruders. This has 2 beams at about 20 cm apart. What it actually does is to transmit the beam across to a sensor this beam is then retransmitted back to another sensor. It works really well and runs on batteries. The batteries last about 2 to 3 years.
Can't remember the make at the moment, but will see if I can find out for you.

[toscal]

Can't find the manufacturers website of the beam break sensor I was talking about. But here is another site of some that I have used for other jobs. Also one of my clients installed A 2PH-30C himself and said it was quite easy, just needed a multimeter to obtain optimal alignment (can be done without but better with). The ones I have used are the Twin beam 2PH-30C. The one that might be of interest to you is the single beam PH30FA as this is designed to be flush mounted.
More info here http://www.siimos.com/ground-3-eng.htm

Hopes this helps

[Kevin]

I have some of the Maxbotix sensors - I intend to mount them diagonally across a door frame ie facing into a room (I have deep door frames) to detect entry exit as wella s direction... Their verbose output is reduced to manageable info via a small PIC based board made by Gerry Duprey. still to try though

https://www.maxbotix.com

[Andrew Millne]

Thanks Guys,

Most of the IR Beam break sensors seem to be a little overkill and obtrusive for my liking. The Maxbotix ultrasonic option looks as though it will be easier to conceal and install.

I like the idea of being able to infer direction of travel as well.

Another thought I had was some kind of capacitive solution as concealed metallic strips would be a nice tidy option but there would be difficulties with direction of travel.

I'll be following your progress on this one closely, thanks for sharing.

[chris_j_hunter]

>concealed metallic strips ...

in which case, maybe good-old switch-mats (switch when walked on, Maplin used to do them, for example) might also be an option ... use more than one, for direction ... etc ?