we are going to work on a countdown timer. The timer will count down in seconds; it can be used for minutes too. We will develop an interface to set the timer value with the A and B buttons. The shake option will be used to reset the timer. We will include a countdown tone for those that have version 2 of the Micro:bit. This is a handy lesson for teachers or students that need a timer for class activities. Apart from being a useful class tool, it teaches several coding fundamentals.