Information required: PIR sensor activated outdoor lights

Discussion in 'General Electronics Chat' started by Korneles, Jul 18, 2016.

  1. Korneles

    Thread Starter New Member

    Jul 18, 2016
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    Kind AAC members,

    First off: English is not my native language and I want to learn from my mistakes. So do not hesitate to correct me when I make a mistake.
    I know there are some Grammar N***'s out there! ;)

    Second: This is my first post, I'm posting here because almost every time I search something about electronics I come here.

    My project:
    I want to make an automatic light. I want to use two PIR sensors, one left and one right and in between a few LED spots.

    The information would like to get from you guys:
    I do not quite know how to say this correctly.. But the idea is the light comes on in about .5 or 1 second en goes out in the same time span. So no hard light but a nice and smooth transition from no light to light. I have a simple sketch of what I think will work (I'll try to upload it). I can add a relay fairly simple, if necessary, but do not know an cannot find information about a simple tool that makes the lights come on with a nice transition.

    So, I hope someone can help me. It's not a very difficult question so I guess this will be solved soon!

    Korneles
     
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Hello Korneles, welcome to the forum.

    Have you selected which PIR sensor and LED spotlight you want to use?

    There are a few inexpensive PIR sensors out for sale that tootle a pin when an object is sensed. That can trigger your LED driver.

    If the LED spotlight is DC powered you can simple pulse width modulate (PWM) the power to get it to fade in and out. Doing something similar with A C is much tougher but possible.
     
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  3. Korneles

    Thread Starter New Member

    Jul 18, 2016
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    Hi ErnieM,

    Thank you for the fast response!

    I plan on making it all DC and 5V with two mini PIR sensors of Ebay. 5 pc for 10 dollar! :)

    The LEDs need some research though. PWM, never heard of it. Just looked it up, looks good! Just hope I can make it work. My knowledge stops here though. Could you give me an idea about what I need to make the pulse width modulate? Adaptor, LEDS (obviously), PIR, and ... ?

    Korneles
     
  4. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    How much power to the lights?
    Are the lights 5V also?

    It sounds like you want this:
    If either sensor detects something, the lights ramp up from dark to full brightness over 0.5 to 1 second.
    The lights stay on as long as either sensor is activated.
    When both sensors are off, the lights ramp down from full brightness to dark over 0.5 to 1 second.
    Is that it?

    What is your skill set? Are you looking for ebay modules to wire together, or a circuit to build on perf board? Also, are there any other power sources available besides 5 V?

    ak
     
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  5. Korneles

    Thread Starter New Member

    Jul 18, 2016
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    Hi there AK,

    Not so skilled I'm afraid. Your description of the setup is correct. That is my plan. The sensors are 5V, my guess was to make everything 5V hoping I could understand it better haha :confused:

    My plan is to wire everything together. If there is need for a circuit board I can figure something out (make one using the required software), but my preferences go out to a (very very very) simple setup so I can do everything myself.

    Well.. not everything.. With some help from u guys! ;)

    Korneles

    Edit:
    why not make it analog :D
     
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    5 volts is a good choice. It can run your sensors, run the LEDs without too much loss (will need some dropping resistors) and also run whatever sits between to make the pulse width driver.

    I don't have a good recommendation for what sits between the sensor and the LEDs. If I was doing this I would use a micro controller, but that is a whole other world for you to begin with.

    I'm hoping some clever lad will come by and present a nice 555 timer based solution or such.
     
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  7. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    It already is.

    ak
     
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  8. Korneles

    Thread Starter New Member

    Jul 18, 2016
    4
    0
    ErnieM,
    I have an Arduino kit. With the Arduino I can make it work. Just trying to make this without. I know it's possible! I heard about the 555 timers. I just don't know how these little guys work. Tried to gather some information so I could use one. Didn't understand anything about it :(

    AK,
    I was trying to make a joke :p
     
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