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PIR Sensor 555-28027 and H/L jumper — Parallax Forums

PIR Sensor 555-28027 and H/L jumper

ionateionate Posts: 2
edited 2011-05-20 10:09 in Accessories
Hello, I'm trying to use the PIR sensor with an XBee radio by connecting the output pin to one of the DIO lines on the XBee. I have a 4.7kOhm resistor tied to output of the PIR, going to the XBee DIO. This all seems to work ok, but when the jumper is in the "retrigger" position, it doesn't seem to work that way.

That is, I get a signal from the XBee stating that the line has gone low, even though I'm jumping in front of my sensor like a madman.

The documentation that it should stay high, but it seems to go back to low regardless.

Any assistance you can give? Any more information needed by me? Thanks in adv,

i0N

Comments

  • Kevin CookKevin Cook Posts: 159
    edited 2011-05-19 11:23
    Do you have any way to verify the PIR's OUTPUT? Maybe put a DMM or Scope if you have it to see if it's triggering. You're connected to the DIN on the XBEE right? What mode is the XBee in?
  • ionateionate Posts: 2
    edited 2011-05-20 10:09
    Kevin Cook wrote: »
    Do you have any way to verify the PIR's OUTPUT? Maybe put a DMM or Scope if you have it to see if it's triggering. You're connected to the DIN on the XBEE right? What mode is the XBee in?

    Thanks so much for the reply. I am actually connecting this to the DIO line on the XBee and not using DIN/DOUT at all.

    The DIO line that I have OUTPUT connected to has a pull-up resistor enabled by default (which I keep enabled) and sends an RF packet whenever the DIO line changes. I verified with a scope and the OUTPUT pin is definitely causing it to trigger, even when I am still moving in front of it.

    It seems as if the retrigger mechanism is _sort_of_ doing it's job, but it's real picky. That is, It's almost as if it works better for specific types of movement or ?

    I allow 30 -45 seconds first, for the PIR to calibrating before using it. I am using 5v to power (will 9V work for longer distances?)

    Should I use a capacitor on the alarm pin to help out, or will I need an MCU to take care of this problem? I would like for it to wait at least 3 seconds to decide if it should retrigger or not.

    Currently, it seems to be set to 1 second. What to do? Thanks in adv!
    -i0n
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