And how would it work if you can't see the sun (cloudy day, or even night time)? I have a better idea for you, and it doesn't require any device what-so-ever - if you're outside, you may sometimes notice that the sun rises from the east and sets in the west, so if its not exactly the middle of the day (12:00), you should be able to know roughly which direction is the east or west respectively, thus finding the north There is another way of finding out, which is a bit more accurate which I was taught during my military service, but I'm afraid its not that easy to explain in words