Detect someone in front of a computer using the smallest available sensor.

Using Arduino Project Guidance
#1

Hello,

I'm trying to create my first project using a tiny arduino but I still don't know how am I going to accomplish that...

I need to be able to detect a person in front of a computer. PIR is out of the question because I need to be able to detect the person as long as he keeps in front of the computer. I though of using the Parallax's Ping but it is too big for my project.

So I'm not really sure of how am I going to do this so I'm asking you: What is the smallest sensor that I can use to detect someone in front of a computer? Something with the size of a 10 cents coin (euros) would be nice.

Thanks!

#2

For those of us that don't use the Euro, 10 Cent coins are 19.75mm in diameter, according to Wikipedia.

There are single element ultrasonic sensors around that size, like http://www.dfrobot.com/index.php?route=product/product&product_id=291.

#3

dxw00d: For those of us that don't use the Euro, 10 Cent coins are 19.75mm in diameter, according to Wikipedia.

There are single element ultrasonic sensors around that size, like http://www.dfrobot.com/index.php?route=product/product&product_id=291.

Yes this one is 19.9mm...just a smidge wider (at the board) http://www.instructables.com/id/Getting-started-with-the-Maxbotix-sonar-sensor-q/

Perhaps you could measure the change of lighting as they arrive and leave, using a photocell which are far smaller again http://www.instructables.com/id/Getting-started-with-the-Maxbotix-sonar-sensor-q/

Or hide a force sensitive sensor in the seat cushion?

Lots of options, Geoff

#4

You could use an IR led and an IR receiver. These are very small and will be able to detect if something is in front of it.

#5