Underneath the LED matrix is an orchestra of 36 reed switches — those little glass gas-filled grains of rice with axial leads that snap together or fly apart in the presence of magnetic fields.

Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was… ...

The Arduino board, a popular open-source electronics platform, serves as the brain of the machine. The magnetometer, a device that measures magnetic fields, detects the presence and movement of ...