Sensor to change computer screen

Other Hardware Sensors
1

Hey everyone, I'm new to Arduino and have a question regarding PIR sensors. My son's 8th grade computer class has asked him to figure out a way to change the state of his computer (close the program he has opened and then open a different one) after someone enters his room.

My guess is that we could use a Arduino and something like a PIR sensor shield to detect the presence of a person and send a signal to his comohter to run a program that minimizes his current application and opens a different one.

Is that even possible?
Can someone direct us where we can start?

Thank you!

2

I'd start with an Arduino Micro or any other variant which has "native USB". (My personal favourite is the Teensy 3.2)

This can be configured as a keyboard, so it can do Alt-TAB easily. Or any other key combination.

But, the keyboard doesn't know which program is open. Windows doesn't tell the keyboard that information. So a second Alt-TAB will bring back the window you tried to hide.

3

He shouldn't be watching those videos anyway!