mariateodorapopescu / vhdl_fsm

A team-project about a fem vending-machine I had in 2nd year of uni

Drink Vending Machine

In this project, we've designed an 8-bit vending machine that provides customers with two beverage options and accepts 1, 5, and 10 lei banknotes. The entire system is implemented in VHDL, a powerful hardware description language.

How It Works

Here's a breakdown of how our vending machine operates:

• Bill Slot: The machine features a single bill slot that accepts 1, 5, and 10 lei banknotes sequentially. A bill sensor provides the processor with a 1-bit input C, which becomes 1 when a banknote is detected. Another 8-bit input V indicates the value of the banknote in lei.

• Beverage Selection: Two 8-bit inputs, S0 and S1, represent the costs of the two beverage options. The values of S0 and S1 can be set by the owner of the vending machine. The choice is a 1-bit input to the machine (Alegerea), indicating the selected beverage type (0 for Beverage 0 with cost S0 and 1 for Beverage 1 with cost S1).

• Purchase Process: If the deposited amount is less than the beverage cost, the processor generates an 8-bit output P to display the deposited amount. Once the processor detects banknotes whose value equals or exceeds the beverage cost, it sets a 2-bit output D for a clock cycle, determining the distribution of the beverage (00 or 11 for no action, 01 for dispensing Beverage 0, and 10 for dispensing Beverage 1).

• Change Return: The machine generates an 8-bit output E indicating that change should be returned in banknotes.

How to Use

Each aspect of the vending machine's functionality is implemented in VHDL. The code provides a detailed understanding of the system's operation. Feel free to explore the implementation and reach out if you have any questions or suggestions.