With increasing access to supermarkets, the human resource required to maintain short queue times is ever increasing. This creates a need for automation in the billing system. A fast and simple solution is to decentralize the billing process. This project mainly aims at reducing queue times by scanning the items when being added to the cart by the customer, than being individually scanned at the billing counter. This is realized using Radio Frequency Identification (RFID) technology. Once the products are scanned using RFID reader and the bill is to be generated, the scanned RFID card numbers are wirelessly transmitted to the billing server/counter using Wi-Fi module. At the billing counter the scanned RFID card numbers are matched against a database and corresponding information such as the product name and product cost are retrieved. Once retrieved, the corresponding product costs are summed, the bill amount could be paid for using digital payment services. Once the payment has been processed, the customer receives an OTP that is to be used at checkout. Code Shoppy
Shopping at supermarkets and malls is becoming more common as the days advance. With increase in number of people purchasing at these places, there has been a significant increase in the billing times in queues. Figure 1 depicts people waiting in a queue at the billing counter. The increase in waiting times is due to scanning the individual items purchased in order to generate the bill. This delay can be avoided by scanning the items to be purchased while adding them to the cart using RFID technology. Once this is done, the customer can request for generation of the bill, pay for it and exit the store
The designed system avoids the task of individually scanning the items and retrieving their information which is currently followed at the billing counters. The scanning of products is done as and when it is added to the cart. Doing so would effectively reduce the waiting time in queues which is as per the main aim of the project. Even generation of the bill is hassle free, wherein once customer requests generation of bills through the mobile app, respective codes are run and bill is generated. Thus reducing to a certain extent the man power involved.
A. FlowChart for On-Cart System CodeThe flow chart shown is Figure 5 depicts functionality of code for the on-cart system.Firstly, the necessary libraries required for programming in Arduino IDE are included. Then, the baud rates of each of the modules are set. The setup for Wi-Fi module ESP8266 and SD card module are done. Once the setup is done the RFID tags are scanned. When all 12 characters of the tag sequence arereceived, it is stored in a variable and a delimiter is added. Scanning is done if there are more tags to scan, otherwise steps for bill generation are performed.
UnitFlowchart for Billig Server CodeThe flow chart shown is Figure 6 depicts functionality of code for the billing server. The cart number has to entered in the mobile app and the submit button has to be pressed. Once done the bill must be generated. Before generating the bill, the server must be connected to the Wi-Fi module. In order to do so, a socket is created and connected to. Then the required information is requested using HTTP GET command. Once information is received it is stored in a variable. The information is a string of RFID tag sequences with delimiters. Then the PHP explode function is used to remove the delimiters and convert from string to array. Then the PHP array_unique() function is used to remove any repeated values. Next the PHP implode function is used which returns a string from the elements of an array and is later stored in a file. Then it is required to connect to a database and throw an SQL query to match each line of the file with the parameter prfid in the table that belongs to the database. If a match is found then the entire row is displayed on a table. The total cost of items is calculated and displayed. On selecting to pay for the bill amount, an OTP is generated.
The designed system is a basic working model that can be evolved into something more efficient than the one currently designed. The scope for further improvements in the system can be listed as:1. There can be a measure to remove items if not wanted after they have been added.2. More efficient and long range RFID readers can be used.3. A GUI can be developed to make the customer experience better.4. A wireless charging docking station could be implemented to charge the system on carts.5. Overall security of the system can be improved by using different encryption techniques.