movement sensor

[julioelectronic]

hi.

I want to design a station of alarms for a house,with pic, but I need to select a movement sensor, I have looked for the data sheets, but I didn't fine it. somebody can help me?

chao

[Melanie]

Do an internet search for Pyroelectric Sensors...

example download Datasheet of MuRata offerings...

http://www.murata.com/sensor/

[mister_e]

And then you'll discover that you'll spend more time to do a efficient sensor than if you just buy a already made one :) It's not as this expensive. Wel that's my opinion.

When you buy one, there's only 4 wires to route to it : 2 for supply and 2 for the contact output (NO or NC)

But if you want to have my own opinion of it, i still prefer to place more contact and glass break than use any motion sensor. In the past (and probably it's still the same thing today), after few years, the sensitivity and accuracy of those sensor reduce. What i try to say is that it seems that the sensor don't react at some place in it's range. Kind of 'blind' or 'spotted' sensor. I know there's somebody here who work in this area.. so if i'm wrong or partially, set me straight!

For the control panel, it's still a good idea to build your own.

[G8RPI]

Hi,
It is probably wore cost effective to buy a motion sensor than build your own. Both Melanie and Mister_e are refering to passive infra red (PIR) sensors.
These are cheap and reliable but can produce false alarms due to warm air currents etc. There are more sophisticated units that have dual detectors, one PIR and the other either doppler radar or ultrasonic. An output is only produced when both sensors "see" a target. Even if you are working on an "intellegent" sensor type system (networked rather than just lots of contacts in series) I'd suggst you buy the sensors (you can't buy the detector, fresnel lens, tamper switch and case as parts for the cost of the unit) and add a PIC to them. You can pick up the signal that drives the relay. Removing the relay makes for a silent unit rather than one that clicks as you go by. A pic is a great choice for the control panel. I-buttons by Maxim-Dallas make great entry keys.

Robert G8RPI.