Design and Implementation of Finite State Vending Machine in Bangladeshi currency

Vending machine is an automated machine which dispenses products such as chocolate, beverages, snacks, consumer products, etc. after a consumer inserts currency or credit into the machine. Due to modern fast paced lifestyle, vending machines are increasing rapidly. Vending machines are being widely used in nations such as USA, China and Japan, for its automation and accessibility. The aim of this paper is to design a vending machine that can supply two products of different prices in Bangladeshi currency. When money is inserted into the machine, it detects the currency and delivers the selected product. Furthermore, the feature of returning the change has also been included.The machine also returns the currency which has been entered mistakenly.It has also been designed to operate within minimum possible time. The design is executed using the Finite State Machine(FSM) approach. It comprises of both hardware and software simulation. The software part is implemented using Verilog code for FSM based machine along with testbenches simulated using Icarus Verilog 0.9.7 in EDA Playground. For hardware implementation Proteus 8 Professional simulation is used.