NXT motors are very easy to use, because of their built-in encoders. But, sometimes kids want to understand, or the teacher desires to explain how to collect information from a rotating axle. (The sensor has got its name because it is made of a light sensor and a sheet of paper only.)

Today you won't have troubles to buy an electronic compass from the shelf. But, sometimes you want to understand - or as a teacher - to explain how the compass direction can be turned into digital information. This sensor got its name, because it is made of a few LEGO pieces, the RCX, a magnet, a li...

Acceleration is a physical concept that is difficult to understand, although you can feel
it when driving on a roller coaster. This sensor might help kids to realize how
acceleration can be quantified. It got its name, because it is made of a few LEGO pieces,
the RCX, and some n...