laser / ir person counter?

[discostuee]

Hi, this may sound strange but hopefully one of you smart people can help me make this.
I have a shop in a small walking area of town but want to know when the busiest time of the day is and day.
I had this idea of perhaps speaking to the other shop opposite me (about 30m away) and asking them if i could put something in there window.
I was thinking that i could put a laser pointer in there window and in my window a small long tube with a light sensor, the light sensor would be connected to either serial or lpt port to my computer that logged the time and date when the sensor light was broken.
Is this possible and if so how do i do all this, i have novice knowledge so assistance would be appreciated.

Thanks
Stuart

 

[srikanthsamaga]

Placing an IR LED and IR sensor also would work. But the major problem in this project is interfernce.
In both cases since this unit is kept outdoor, there are many IR and light sources that cause disturbance.
Instead if legal, you can use a camera and with some image processing.

 

[ronsimpson]

I> think you do not want to put electronics in your neighbors shop. (laser)
>You could put a mirror next door but the alignment is very hard.
>A bicycle reflector reflects light back to where it comes from. (truck reflector) There is no need to align the reflector. I could sneak over and attach a reflector to the neighbors. At night shine a flashlight over there and it should reflect back. Then shoot a laser over and you should get it back.
>Radio Shack sold a security sensor that shoots a beam of IR light across a distance and back (using a reflector). It was built to sound an alarm but the contacts could go to your PC. It clams 30 to 100 feet but really could not do that.

 

[alec_t]

Laser pointers are powerful enough to cause permanent eye damage, leading to lawsuits; so don't go there. Stick with IR.

Alec