Hi. I am a student in second year. My project is to design a digital circuit which operates like a vending machine. There are five juices (e.g. pepsi, 7up, etc) and the machine can carry only three of each. the coins that can be used are (10, 20 and 50 cents). You can buy a juice for 150 cent. I have attached the description of the project.
I want some hints guys.

THANKS

 

Begin with listing the functions the controller must perform. For example, it must detect the presence or absence of a 0.2 ringgit coin dropped in the slot, and increment the count. It must detect whether there is a container in each que.

I suggest compliance with "include additional specifications which you think necessary" by giving change and by refusing to accept money if there are no containers in any que. For example, if I put in a pair of 50 sen coins and a trio of 20 sen coins, I'm going to want a dime back!!

Once you have the list of functions, you can work toward making them happen with the required and suggested circuit elements.

 

Thanks sir. I appreciate that very much.