Simple test bed for PIR sensor (Non-module).

Discussion in 'The Projects Forum' started by Rstoone, Jul 17, 2016.

  1. Rstoone

    Thread Starter New Member

    Jul 17, 2016
    4
    0
    This is my first post. Assume I know the very, very, very basics of electronics.

    Trying to make a stand alone PIR Sensor Test Bed.

    Equipment used:
    * Bread board (6" x 2")
    * Panasonic PIR Sensor (Non-module) P/N: EKMC1603111 (Digital Output?)
    * 470k ohm resistor
    * Blue LED
    * 5v AAA - 4 battery caddy
    * Jumper wires.

    I want to make sure I give you as much info as possible. Sorry if over compensating but
    I hate when people don't give you all the info needed to give a good answer.

    PIC of project:
    [​IMG]


    PIC of diagram used:

    [​IMG]



    When power is applied to the project the blue led flashes a pattern continuesly:
    2 blinks (.75 sec) pause, 2 long blinks, pause for 1 sec, repeat.
    If I wave my hand over it, it will totally change the pattern to fast blinks, some long
    blinks and some short pauses.

    Things I think I did wrong ?
    1)...Using a diagram that uses a Modular PIR Sensor?
    2)...Need a frame or earth ground also?
    3)...The PIR sensor is a digital output and the above drawing is analog ???
    4)...The blinking blue light is telling me what I'm doing wrong in Morse code but don't know Morse code?

    Thanks in advance for your help.

    Rob
     
  2. AlbertHall

    Well-Known Member

    Jun 4, 2014
    1,969
    388
    From the datasheet for this device, it has a 30 second settling time and during that time there will be output pulses not related to whether it detects anything.
    Also the maximum current from the digital output should be <100uA, which means you can't directly drive an LED. The diagram from the datasheet is:
    upload_2016-7-17_23-32-46.png
     
  3. Rstoone

    Thread Starter New Member

    Jul 17, 2016
    4
    0
    ================================

    AlbertHall,

    Thanks for your quick response.

    Questions:

    So if I'm understanding this diagram correctly. I put a dedicated 5vdc to the Vdd and GND.

    Then I have a 2nd dedicated 5vdc that goes to a NPN Transistor and then there are 2 resistors involved.

    Remember I novice.

    What would be the values of the 2 resistors and what is the part number of the NPN Transistor?
    Last. Where can I put the LED? and is there anything else to make the LED work correctly?

    Thanks in advance,

    Rob
     
  4. AlbertHall

    Well-Known Member

    Jun 4, 2014
    1,969
    388
    You will probably be OK using the same supply for both. However, if whatever you are actually switching needs a lot of current that may interfere with the sensor operation then you may need decoupling. Not a problem while you're only driving an LED.

    For the resistors, 47k would be a good value (gives just under 100uA)
    Any small signal NPN transistor will work.
    Put the LED and its 470 Ohm resistor where the diagram shows the load.
    That should do it.
     
  5. Rstoone

    Thread Starter New Member

    Jul 17, 2016
    4
    0
    Simple PIR test bed diagram - ZOOM -1.jpg

    It not perfect but does this look correct ?
     
  6. AlbertHall

    Well-Known Member

    Jun 4, 2014
    1,969
    388
    Yup, except the resistor in series with the LED should be 470 Ohms.
     
  7. Rstoone

    Thread Starter New Member

    Jul 17, 2016
    4
    0
    Will build it and let you know the outcome.

    Thanks,

    Rob
     
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