First of all, i'm not very experienced with Arduino (have done 1 project before, with a servo), so please keep that in mind :P
The purpose of this project is to play one song repeatedly when a person is in the room. I want to achieve this by attaching a arduino MP3 shield on a arduino UNO. My idea for recognizing people entering the room is to position a push- button switch in the door- frame. In that case the song should start playing when de door is opened. The problem is that the song will stop when people will close the door behind them (the song should stop when people leave the room). Do you guys have any thoughts about this, or maybe a other solution then the push- button switch (I was also thinking about a IR- sensor)?
Any help would be more then welcome!