Connecting PIR motion detectors to Raspberry Pi

BobS0327

Active Member
EDIT Should have posted this in the General Automation forum.
 
Unfortunately, I'm hardware challenged and have absolutely no idea how to interface a DSC Bravo 6 indoor PIR and a Optex LX-402 outdoor PIR to  a Raspberry PI (RPI) computer.  I can't find anything on the internet that I can use.
 
The documentation indicates:
 
Bravo 6 Current in alarm  (LED on)  25ma
Bravo 6 Standy current  17.5ma
 
Optex LX-402 Alarm output NC NO 28V DC 0.2 A max
 
The above info makes absolutely no sense to me. 
 
Any info would be greatly appreciated
 
 
 
 
Went looking ...well too the references related to an Arduino project but it would be similar to an RPi project.
 
Bravo 6 Current in alarm  (LED on)  25ma
Bravo 6 Standy current  17.5ma
 
is just the draw of the Bravo 6 indoor PIR.
 
Optex LX-402 Alarm output NC NO
 
28V DC 0.2 A max - 28VDC means it can take a maximum of that voltage through the contacts with a 0.2 Amp draw.
 
Thinking the RPi is going to utilize 5VDC eh? such that it is not an issue.
 
Goofing around with that whole GPIO / i2C stuff seeing here its either 3VDC or 5VDC that I need for aux circuits stuff.  My little test board used 5VDC to drive a 3VDC circuit the size of my thumbnail.
 
Here I have purchased already fitted sub boards (shims) which are typically documented and have ventured to direct GPIO connects.  This stuff though is typically documented on a per project base.
 
So here its been a best guess (not a good thing?) using iC2tools and just connecting and disconnecting wires and watching.  
 
You can now also purchase a cheapo logic analyzer clone these days for $10.  The clones are on Amazon for a bit more with Amazon Prime delivery.
 
file.php

 
 
 
You can also just add a digital IO board if you want for your testing which would make your stuff easier to test.
 
Here is a quickie drawing relating to a PIR.  Note that you can change the GPIO.
 
PIR-RPI.jpg
 
Thanx for the info.
 
Unfortunately, I have just enough electronics knowledge/experience to be dangerous.  I think that maybe I should order a few extra backup RPI's just in case. I'll probably end up "frying" a couple in my learning experience.
 
Order a breadboard kit for your RPi.   It is all plug n play. You cannot break anything.
 
breadboardkit.gif
 
 
 
Just using a breadboard does not mean you can't break anything.  And I certainly wouldn't call it plug and play - that generally means you can only plug it in one way and it just works.  You are still connecting directly to the GPIO pins and could damage things. 
 
Use your googlefoo...  If you search for "raspberry pi buffer gpio" you will get lots of products and designs.
 
I have used transistor buffers between the sensor input and the GPIO pin.  Also useful on outputs for driving higher voltage/current than the pins can drive directly. 
 
I have also used an arduino for io to a pi or beagle bone board.  Arduino Uno clones go for about $6 and has a replaceable chip for half that.  Cheap to replace if they get damaged.  You could start with just the uno until you figure out a bit more...
 
JimS said:
Just using a breadboard does not mean you can't break anything.  And I certainly wouldn't call it plug and play - that generally means you can only plug it in one way and it just works.  You are still connecting directly to the GPIO pins and could damage things. 
 
Use your googlefoo...  If you search for "raspberry pi buffer gpio" you will get lots of products and designs.
 
I have used transistor buffers between the sensor input and the GPIO pin.  Also useful on outputs for driving higher voltage/current than the pins can drive directly. 
 
I have also used an arduino for io to a pi or beagle bone board.  Arduino Uno clones go for about $6 and has a replaceable chip for half that.  Cheap to replace if they get damaged.  You could start with just the uno until you figure out a bit more...
When you have long runs to external devices, you need more than just input protection. Long runs will pick up noise, and this could cause false trips.  Ever zone on an Omni or Elk has a current regulated source. When you use an EOL resistor (and even if you don't) the voltage across the resistor and sensor with this fixed current source is measured with a rudimentary voltage meter built-in to each zone. Only when a zone is faulted for a given amount of time (~300 ms) does the zone trip. 
 
Alarm zones are much more sophisticated than what first appears.
 
Understood.  The breadboard just gives you more space.to play.  Yes there are many experiments out there in internetlandia.
 
I call everything plug n play after I have done it once or twice.   You know that as I always write it so.
 
Here went slow soldering one strand of one wire. Dropped a drop of hot melt glue; then used the hard air gun for a few seconds.  I use painters tape which works for me.
 
SCLSDA-2.jpg
 
Here mostly with the RPi's just configured them as servers and do not play much with them.  The parts are very modular.
 
It is understood you are tinkering with this stuff to see how it works. 
 
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