How to build vending machine?
You need to identify your product, and audience first. Once thats sorted vending machines are pretty simple machines: They require at a minimum: A housing, preferably secure from vandalism A user input output section, buttons and a screen A means to retrieve money from the user, and possibly give change A more-secure place for the retrieved money to store in A means to store the product inside where it can be vended mechanically A means to vend the product to the world. An arduino could easily serve as the ‘brain’ – it can talk to motors, buttons and screens. Coin mechanisms are most common, but you could use magnetic cards on a proprietary credit system, or just a password (like at a carwash or net cafe, where the clerk gives a one-time-use password to activate the unit) Vending depends on the product, screw-style vending is common for solid objects.