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Old 12-02-2010, 02:00 PM
pavan.venkat19 pavan.venkat19 is offline
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Arrow persons counter in a room

hai guys, this is pavan studying b.tech,i am doing project to find the no people in the class.when the person enters the room count to be increased,and when they walk out count to be decreased. i thought that if two sensors (are used depending on the sequence of their on and off ), up\down counter,7 segment display task can be achieved,please help giving relative circuit diagram and functioning i too shall try my best please help
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Old 12-02-2010, 02:09 PM
jpanhalt jpanhalt is offline
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Old 12-02-2010, 02:16 PM
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Hello,

As this is a class assignment, I moved it to the homework section.

What have you done upto now?
Do you already have an idea how to detect the persons goin in or out?

Bertus
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Old 12-02-2010, 02:33 PM
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The idea might work. Where and how would you place the sensors (what specific sensors?)? What kind of logic will you use, and what schematic have you come up with? How many people must you be able to count?

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please help giving relative circuit diagram and functioning
This is your assignment. If we did that, it would be like helping you cheat.
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Old 12-02-2010, 06:59 PM
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Georacer Georacer is offline
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I have done something similar (teacher tracking) and have used a microcontroller. A logic circuit implementation might be doable in theory but I don't know whether it could in fact be reliable.

You are on a good way assuming you will need two sensors for the direction recognition. I have used cheap lazers on one end and an optoresistor on the other. Simple and works! It has some speed limitation however; I wouldn't trust it for a reaction time of less that 100 or 50 ms.

Take into consideration the following:
You don't want a foot to be able to block both sensors at the same time.
You don't want to miss a foot going over your sesnors. That means you have to mount them at about 30 cm from the ground.
You don't want to count twice for each person (2 feet crossing).
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Old 12-02-2010, 08:24 PM
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Is the circuit for an idealized "single file entry / exit" system, or reality.

If the latter, is there any time where one person would be leaving at the same time as one was exiting?

Can more than one person enter the room at at time?

That isn't as easily figured for. An accurate continual count would be a video system with "head shape" recognition, then count the hits, but that is a bit out of the realm of your circuit.
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