In this project, we create a joystick-controlled laser by connecting two servos to a joystick and using this setup as a pan-and-tilt controller for a laser pointer.

If you aren’t familiar, the digitalWrite () function is one of the key functions Arduino gives you to operate its boards– specify the pin and the value (high or low) to drive it.

He’s using this to bypass the extra cycles used by the Arduino’s in-built loop () function. The only command that is run within his hacked loop is a deeply nested set of macros.