People Counting Circuit!

Discussion in 'Homework Help' started by Lokey_Alwin, Nov 15, 2014.

  1. Lokey_Alwin

    Thread Starter New Member

    Nov 15, 2014
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    Hello, do any of you guys are familiar with a people counting project, which uses IR beam detector, and seven segment displays to display the number of entrants? If so please help me. I would like to do a project like that, but have no idea where to begin from.

    thanks
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    You start with block diagram.

    You already listed a sensor block, a display block. Now you need a block that connects the two.

    Then you put stuff into each block. Like sensor block gets IR beam detector.

    Now that you know what goes in each block, you design a circuit that makes that main component work.



    Since I am lazy, I would get an Arduino board, and connect the sensor and display to it. The fact that other people already done something like that with their Arduino boards means that I have to do very little work. I can just copy their hardware and software setup, maybe modify a few things in the software.

    I can sort of see in my mind how to do it using just analog components. So it can be done either way.
     
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  3. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    Curious, why are you thinking about doing this project?

    Is there an entrance and is it only one way? You didn't mention it, so I assume not. Other than that shteii01 has given you some very good advice.

    By the way, is this an assigned project?
     
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  4. Lokey_Alwin

    Thread Starter New Member

    Nov 15, 2014
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    of course this wan an assigned project, only to practise electronic components, however our professor asked us not to use arduinos. So I guess I have to use counter ICs or so. But I do not have a very good idea about these counters. And is it possible to stop over-counting? I mean, when someone enters and breaks the IR beam, will that increase the counter continuously except incrementing by just 'one'. Can we delay such a counter to get incremented only by 1 and wait till the entrant fully passes the beam?
     
  5. Lokey_Alwin

    Thread Starter New Member

    Nov 15, 2014
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    thanks
    shteii01, but we are not allowed to use arduinos. So how can I get the same result by using ICs. I actually have no good idea. I only know that there are counter ICs, decorders which helps to decode and also to attach seven segment displays. How should I start? :/
     
  6. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    Since this is Homework, you need to show some work. Read this post on submitting homework questions. You should have submitted this in Homework Help. Note the forum name is not Homework Done For You. We will guide you to a solution and help when you get stuck.

    How should you start? Find a counter IC and read it's datasheet. Note there are binary and decade (decimal) counters. Then, do the same for a (BCD to 7 segment) decoder IC.

    Are you familiar with counting ICs? Read their datasheet, and it will answer your question about stuck counting. Look for what's necessary for the count to change.

    Moderator: Should be in Homework Help.
     
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  7. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Moved to the homework section as suggested.

    Do you need to count the incoming and outgoing people?
    If that is the case, you must determine if one is coming in or going out.
    When one is coming in, the counter must add 1, if one is going out, the counter must be lowered one.

    Bertus
     
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  8. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    I told you what to do (block diagram). You have not done any of it. Story ends.
     
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  9. Lokey_Alwin

    Thread Starter New Member

    Nov 15, 2014
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    actually counting incoming people will be enough for this project! I read some datasheets, still I got some problems with delaying the counter to get incremented only by '1' when a person breaks the IR beam. I am not that much familiar with datasheets however.
     
  10. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    When people are leaving the room, the counter will also be incremented.
    When all people that came in also left the room, the counter will show the double amount.

    When you want to discriminate between incoming and outgoing people, you will need two IR beams separated by a certain distance.
    When someone goes in, beam 1 will be broken first and then beam 2.
    When someone is going out, beam 2 will be broken first and then beam 1.

    Bertus
     
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  11. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    I think you are making the scope of the problem bigger than it needs to be or wanted.

    Like you said, person comes in, break beam, count is up 1. Person leaves, break the beam, count is up 1. Double counting.
    How do we fix this in a simple duct tape fashion? Easily!
    Use separate lanes/doors for entrance and exit. Put your sensor at the "entrance door". Now you ONLY counting people who are entering the room. No more double counts.
     
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  12. Lokey_Alwin

    Thread Starter New Member

    Nov 15, 2014
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    that'll do the work. Yet overcounting one person is a problem I hope. When someone is breaking the IR beam, will the counter get incremented rapidly rather than getting incremented by '1'? Is 555 timer not re-triggerable while sending an monostable output? If so, can I use that 555 timer to filter unwanted sensor(IR beam breaker) inputs?
     
  13. WBahn

    Moderator

    Mar 31, 2012
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    Think about how you would do it if you were shown a punch of pictures taken at a uniform rate of, say, ten per second and all you could see in the picture was whether a flashlight pointed at the camera was blocked or not. Let's say that each object passing in front of the flashlight typically takes between 0.5 s and 1.5 s to cross.

    So I show you a picture and the beam is blocked. What information about the last picture I showed you would you need to remember in order to know whether to count this picture as a new object passing in front of the flashlight or not count it as an object that has already been counted but is still blocking the beam?

    There are some other things that your design should address, even if it does so by stating assumptions in your report. For instance, what if two people come in side by side? What if one person comes in swinging their arms so that their forward-swinging arm breaks the beam, their body breaks the beam, and then their backward-swinging arm breaks the beam?
     
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