A while back i stumbled on a page that implemented a TTL (and more?) counting system to determine number of occupants in a given room.
I have been: 1)trying to search for that page but i cannot for the life of me remember what the title of the post was
2) trying to come up with my own simple low cost solution to this.
I have been thinking on the lines of some IR led's and a µContoller but with the programming etc... i feel as if that is a bit extensive for just a counter.
I have a few ideas such as:
two IR LED's separated at 'X' distance. When the beams are broken in sequence it will indicate a direction. I wish to add a value to either a register, or seven segment display each time someone enters and the opposite when someone leaves.
So far im not worried about two people entering simultaneously ill handle that later. I just want to build a working prototype for now.
My reason for this post is because i cannot find the other posts that may have helped me first. So now i am asking for the first step in this process... What would be a better method; strictly µController and IR leds, or perhaps a TTL system.
I pulled out my digital logic book but considering it has been over 2 years since i took the course i dont remember much. This is why i kind of want to side with the TTL method to refresh my memory.
Any help is appreciated
thanks