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Took a Short Cut IR Dectector Help Please — Parallax Forums

Took a Short Cut IR Dectector Help Please

Ken_tnKen_tn Posts: 16
edited 2010-05-30 04:47 in Accessories
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Not being very good building electronic circuits I purchase what is call a PNP IR board. Unfortunately it did not come with much in documentation. It has 3 pins GND, +5V, and TTL output. Here are the instructions I got.
1.)· Connect 5V to Pin 1, Ground to Pin 2
2.)· Connect Pin 3 to MCU input Pin
3.)· Adjust the blue variable Resistor to achieve desired sensitivity.
I purchased it off EBay and it said perfect for Object Detection or Object Distance. But the documentation sure sucks. If anyone has any code examples they think might work with this I sure would appreciate it. I was thinking that some kind of pulse must have to be put out on Pin 1 and then read results on Pin 3

I know this forum is for Parallax equipment, but I am using a Basic Stamp. [noparse]:)[/noparse]

Comments

  • hover1hover1 Posts: 1,929
    edited 2010-05-29 20:10
    Ken

    You would not pulse pin 1, that is the power pin and power has to be supplied all the time. I have seem these sort of devices on ebay claiming distance measurment, but they are just object detection. I suspect the variable resistor will just adjust sensitivity. You will see pin 3 go High or Low when an object is in view of the sensor.

    Do you have a link to the ebay auction?

    Jim
  • Ken_tnKen_tn Posts: 16
    edited 2010-05-29 20:16
    The Ebay Link is: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150321562175&ssPageName=STRK:MEWNX:IT·
    All I want really is object detection, but will take distance if I can get it. LOL
  • Ken_tnKen_tn Posts: 16
    edited 2010-05-29 20:36
    Would this work like Parallax PIR sensor then?
  • Ken_tnKen_tn Posts: 16
    edited 2010-05-29 20:58
    I hooked it up and found it not bad for object detection. Pin 3 goes high when object detected and goes low when not. Kind of simple but works.
  • hover1hover1 Posts: 1,929
    edited 2010-05-29 21:30
    Yep, just like the Parallax PIR.

    The PIR is just about the same price right now @ $7.99 each, but with better documentation. tongue.gif

    Jim
  • Ken_tnKen_tn Posts: 16
    edited 2010-05-29 23:09
    I have always been happy with the product I have purchased from Parallax, but I got a PIR in the other day from them and never was able to get it to work. Also from other posts I have seen there may be a problem with their PIR units. Thanks for all the help. Also, this unit does have a nice feature that you can adjust the distance of it with a turn of a screw.
  • hover1hover1 Posts: 1,929
    edited 2010-05-30 00:35
    Yes Ken,

    I have noticed that some people have been having problems. I have three working just fin for the last year. I'm not sure what the problem is.

    And I do like the variable pot on the one that you purchased. Nice feature.

    Jim
  • PrettybirdPrettybird Posts: 269
    edited 2010-05-30 01:33
    · I chatted with that guy that makes those sensors. He wanted me to help him sell in the US. I have seen a video on that sensor and it seems to work fine, but I couldn't get a good price break. It is not a PIR sensor. A PIR detects change not distance. Here is some imfo I got from him. They have a 1 IR and 2 IR sensor.but the circuitry is probally the same. I made my own and posted it in the·BS2 room a couple weeks ago.

    Post Edited (Prettybird) : 5/30/2010 1:39:06 AM GMT
    IRNG3.jpg
    696 x 480 - 46K
  • hover1hover1 Posts: 1,929
    edited 2010-05-30 01:50
    Granted , it's not a Passive Infrared system. It's a little hard to determine with the little information they have on the ebay website. They do not tell you how to calibrate it. Maybe just turn the pot until you get, say, 12" for detection? Then it will only detect an object within 12" or less?
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-05-30 04:47
    Maybe I'm wrong, but it looks a lot like the kind of thing that's described below:

    See "IR Object and Distance Detection with NCO and DUTY Modes", page 147 of Propeller Education Kit Labs manual.
    www.parallax.com/Portals/0/Downloads/docs/prod/prop/PELabsFunBook-v1.1.pdf

    Except maybe instead of adjusting LED brightness with the NCO, it just uses the blue pot.
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