Build an RGB lamp that automatically changes color based on ambient light using three LDR light sensors and the map() and analogWrite() functions.
Wire four servo motors to an external power supply and control them together in full synchronization via the Servo library, with a safety note on power supply.
Build a countdown timer with hours, minutes, and seconds set via a keypad and shown on an LCD, with an audible alert when time runs out.
An introduction to Bluetooth technology, the origin of its name, and how it works via 2.45GHz radio waves and the device pairing mechanism.