BBC micro:bit – Ticketing System

Your challenge consists of programming your BBC micro:bit to use it as a ticketing system. Ticketing systems are used in a shop to control the order of the queue of customers:

1. The queue should start at the value 0, and should be displayed on the micro:bit LED screen.
2. When a shop assistant is available they press button A to call for a customer: The queue number displayed on the micro:bit should increase by 1.
3. The shop assistant should be able to cancel their action by pressing button B: in this case the queue number should decrease by 1.
4. To reset the ticketing system, the shop assistant should press both A and B buttons simultaneously. The queue number will be reset to 0.

Solution