In cities, you can find many vending machines at airports, bus terminals, offices, and campuses. Imagine you are at a bus terminal and you are thirsty. You can buy a beverage bottle directly from a vending machine. This is one of the scenarios of vending machines' operating environment.
A vending machine consists of various products. Users can select the product that they want to buy. After selecting the product, users pay by inserting coins or payment cards such as debit/credit cards. If payment is confirmed, the vending machine will deliver the selected product to the users.
You can see a vending machine in the following figure. You can check it out at https://www.samsclub.com/sams/seaga-16-snack-and-14-beverage-full-size-combo-machine/117240.ip:
In this chapter, we'll learn and explore how vending machines work and how to build one for...
