PDA

View Full Version : Wireless Motion Sensors.



koossa
- 5th October 2006, 10:35
Hi Picers!

I am a software/web developer, and only know the very basic electronic stuff.

I have develop a few small electronic projects with a LCD, keypad, EEPROM etc and using picbasic to control all of it. So my knowledge is limited.

I'm struggling to get a good night's sleep because I always hear things outside, so what I want to do is to develop a wireless motion sensor.
My Door chime is wireless and can work up to 100m. I have opened it and the electronics look fairly simple.
I'm not sure how I will be doing this and where to start.
I want to create a couple of units that each has 2 sensors in, 1.2 meters apart so that it only picks up people (Each Unit will be a zone)
It must then send a signal to a main unit that lies next to my bed.
The Main Unit must only make a beep and switch on a led for the zone that was triggered.

Is this a difficult project?
Any ideas where I can get started?

sayzer
- 5th October 2006, 13:51
Would this be the idea?


--------------------

<img src="http://img6.picsplace.to/img6/26/PIR.GIF" alt="Image Hosting by PicsPlace.to" >
--------------------

koossa
- 5th October 2006, 14:10
Hi Sayzer

Thanks for your reply.

Yes, this is a perfect diagram of what I want to do. (and sleep like a baby!!)

How would I get started and where can I get info on how to do it, I have no knowledge on PIRs or RF?

koossa
- 5th October 2006, 15:05
What type of sensors can I use as a motion detector and which one works the best?
- The infrared type sensors are PIR sensors.
- Then you also get a laser type of sensor?
- ?

sayzer
- 5th October 2006, 15:16
Whichever you pick, the idea is simple. Say you have 8 of them; just put them on a Port like PORTB, and transmit the whole portb via RF. That is all.

Then, your byte being transmitted will look like 00000111 as you know, and 1s will be the ones under detect, 0s not yet detected.

I suggest PIR modules as complete unit. There are cheap ones at around US$5.00. You provide supply voltage (usually 110/220V) and you get a relay On/Off output. Connect the relay outputs directly to your pic pins. When the relay is ON, the pin will be pulled low, when Off the pin will be pulled high by a resistor or internal weak pull up etc.

Should be easy to implement.

Rx part is also easy. Put leds on say PORTB again. Drive the whole port by incoming byte from RF module. That is all.

---------------------------

paul borgmeier
- 5th October 2006, 15:20
From experience, my babies didn't sleep all that well (my eyes were red to prove it) - careful what you ask for.

For PIRs, check out this site. Some of the links are for wireless PIR hacks.

http://www.jesseshunting.com/site/homebrew-cams.html

koossa
- 5th October 2006, 15:40
Thank you very much!!

BGreen
- 5th October 2006, 19:18
Most of the sensors that were hacked there are out of production and have been for several years. You can buy motion activated camera controllers from several sources but they can get rather expensive for your purposes. I'd recommend getting a less expensive battery operated PIR and tapping off the output pin of the opamp. on an 8 pin it is normally pin 7, however on a 16 pin you may have to download a Data sheet for the particular device since my brain has decayed and I can't remember which pin it is.

mugwamp
- 11th October 2006, 14:29
There's floodlights available at http://www.smarthome.com/4080xt.html which will send an alarm when they activate using your power lines. They also sell a X10 motion detector without the lights for about $25. It seems that this would be the easiest way to install what you want without stringing a lot of cable. Interfacing a PIC to X10 seems fairly easy although I've never done it.

EDWARD
- 17th October 2006, 21:57
i was just doing some reading in here and I came across your post. I have alink for you. it is a toy that can be hacked to suit your needs. one main problem with it is it's reliability. but it might ave you some time and money. i modified the reciver board to communicate with a pic. The receiver board is a lot smaller then the big plastic toy housing, so it will fit in a much smaller box. the sensors/transmitter are smaller then hockey pucks and have decent range. maybe 20-30 meters
have fun.

http://www.shopwildplanet.com/prod/WPT70044.html

Spy Gear Spy Toys

Spy Tracker System

25$