Sometimes you can switch lights without a direct connection to the mains, however – like this project that interfaces mechanically with a standard light switch.

It looks simple enough – a 64-LED matrix illuminates as the pen draws shapes. But how does the circuit know which LED is under the pen? Good old fashioned matrix scanning is the answer.

Most of us have an 8x8 LED matrix from one of our Arduino kits. What can we do with them? This module investigates how to use these interesting devices. Along the way, we describe a fun electronics ...