Hello People, I'm currently doing our homework
Our teacher gave us this problem and conditions:

A Simple Entry/Exit Counter
Entry: Count Up
Exit: Count Down
Max. Count: 100
Min. Count: Zero

using transition of voltages


Is there someone who could give me an idea of how to start it? If possible maybe someone can provide me a circuit diagram. It would be a very big help for me.

Thank you so much people!

 

As this is homework, supplying a complete project is not what we are here for. We will help with your project, but you must make the attempt.

You have to count up and down - that's a job for an up/down counter IC.

How do you propose to "see" people entering and exiting? How can you tell if they are coming in or going out?

 

our circuit will only be done on a breadboard and not on actual..and i have been googling it but all results are leading n the use of sensors. our professor do not suggest on using sensors..becoz we are not on that topic yet..can you kindly give us any hint on how to do this..?

thank you!

 

One of the oldest ways to detect the passage of a solid body is with a light source and a photosensitive sensor. With visible light, CdS cells work. With IR, phototransistors work well.

Googling "sensor" does not produce useful results. Try "light sensor".

 

is there any alternative way than using sensor in entry/exit counter?
..how can i CASCADE 74191 counter?

thanks!!!

 

You are trying to count people and display the count. The '191 is a binary counter. You would find life easier using a BCD counter, like the '190. The data sheet will give you valuable information.

If you want to place switches under floorboards that get pressed down when somebody goes in or out, that might work. How can you tell if they are going in or coming out?

 

Are you sure you are supposed to use a sensor? Breadboard circuits tend to be more educational-oriented in learning institutes. Perhaps you could just have two buttons: one for a count-up and one for a count-down.