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Using the Prop with the Parallax PIR sensor: no good for outdoor use? — Parallax Forums

Using the Prop with the Parallax PIR sensor: no good for outdoor use?

ElectricAyeElectricAye Posts: 4,561
edited 2010-04-02 00:40 in Propeller 1
I've been pondering the construction of a perimeter alarm to use during camping, to wake me up, for example, when grizzly bears decide to convert me into a midnight snack. I was wondering if the Parallax PIR might be good for that but the manual for this (www.parallax.com/Portals/0/Downloads/docs/prod/audiovis/555-28027-PIRsensor-v1.4.pdf ) states the following on page 3:

"Note: This device is designed for indoor use. Operation outside or in extreme temperatures may affect stability negatively."

So I've been wondering what is the problem with outdoor use? Are they worried about rain, etc? or just relatively rapid changes in temperature? If temperature changes are what they are worried about, could on-board temperature sensors be used to help compensate? I've never played with these before so I was wondering if anyone had ever used one with the Prop and its associated OBEX objects. I'm also curious about their power consumption: would a light weight battery powered version even be possible?

thanks,
Mark

Comments

  • JonnyMacJonnyMac Posts: 9,208
    edited 2010-04-01 21:36
    My [noparse][[/noparse]EFX-TEK] customers use that PIR outdoors in all kinds of conditions. You can easily shelter the PIR in a PVC end-cap; the bigger the cap, the wider the field-of-view. Many of my customers create a PVC "snoot" to limit the FOV in dark attractions.

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    Jon McPhalen
    Hollywood, CA
  • Dr_AculaDr_Acula Posts: 5,484
    edited 2010-04-01 22:56
    Outdoor works fine. You need to make it waterproof if using it in the rain. The only problem is with temperature. The sensor 'sees' the colour of body heat (36-37C) and if the ambient temperature happens to be 36-37C then the sensor can't see you. Or the bear.

    From a practical point of view there are times here in Australia in summer when sensors do not work. However, that is generally during the day. There would only be one or two evenings a year where the temperature is that warm.

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    www.smarthome.viviti.com/propeller
  • mikedivmikediv Posts: 825
    edited 2010-04-01 23:57
    ElectricAye I used mine as an alarm for when my dogs decide to get into the garbage pails,,(quite often) I just tucked it in a spot on my outside garage door where it would get direct rain or snow on it, I live in New England Ct we had a fairly snowy winter and it has been out there for over 6 months now and works just fine. I would not let it get rained on or anything like that but the temp here went from -5 to a now 70 degrees and its going strong
  • mikedivmikediv Posts: 825
    edited 2010-04-02 00:00
    DR_A reading your post to be honest I never really gave the cold that much thought but after reading your post it could be that my PIR is not getting that cold since my garage is heated even though I have it mounted outside its right against the door jam so maybe it is keeping it warm because it has always worked all winter for me every time I would go near it it has always triggered the alarm
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-04-02 00:40
    Thanks everyone. The PIRs were on sale today so I went ahead and bought one to check it out. I just need to figure out what to use as a "test bear".

    smile.gif
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