I started with simple state machines last week. This week I want to talk about more complex state machines and interrupts. These are software topics but we’ll get back to the hardware soon.

The karaoke buttons that control music playback are far more complicated than either its disco button or the quadcopter’s power on sequence; if you press play on the karaoke, what happens? What if the door is open? What if there is no CD? What if it is already playing?