Billing Automation for Supermarkets

Billing Automation for Supermarkets

Related work presents the different techniques proposed by the researchers related to Iot based shopping mall. In paper [1] author has discussed the current problem of waiting in a long queue during billing process and there is a huge amount of rush at the time of festival to avoid this problem author proposed smart shopping cart. It consists of LCD, barcode technique, microprocessor, and Bluetooth. Barcode is used to scan the items which are purchased by the customer and it will store it in the database Microprocessor is used to calculate the total price for all purchased items and display on LCD, the total bill is sent to the owner using Bluetooth and generates the sales slip. It saves the customer time with less effort. In paper [2] author proposed IoT based intelligent trolley for the shopping mall. In the shopping mall, all products are tagged with RFID tag. RFID reader reads the product name and cost of the product will be displayed on LCD. Total amount will be sent through ESP cable to the owner.  

In paper [3] author discussed the current problem of waiting in long queue for billing process and every time user has to pull the trolley for selecting the item. To avoid this problem author proposed smart trolley system for automatic billing using RFID and Zigbee. RFID is used to identify the products name and cost. Later, it will be displayed on LCD. Using Zigbee we can transfer the total amount to the owner. In paper [4] author discussed the current problem of shopping mall for buying the items, which requires a trolley. A customer has to check those items and need to compare with his pocket money. So, to avoid this problem author proposed smart trolley in a mega-mall. It is microcontroller based automatic trolley and it chases the customer while, he is buying the items and it will maintain distance little bit away from the customer. A customer has to place the products which are in front of the color sensor which detects the color wrapper of the product and it will display the product name and cost on LCD. In paper [5] author proposed a new technology of smart shopping cart using Zigbee and Rfid. In shopping mall every product has equipped with RFID tag. It will read the product name and cost will be displayed on LCD. Zigbee is used to transfer the bill wirelessly to the owner. The user has the facility to check the availability of the products which is present in the mall. Using Tablet computer customer can search the products which are present in the cart. During purchasing, if a customer wants to remove any product from the cart he will press the key then that product amount will be detected and total bill will be displayed on LCD.
  
A. On-Cart System Description  
The block diagram of the On-Cart System is shown in Figure 2. The cart is fitted with the Arduino Mega interfaced with the RFID reader EM18 [2], the Wi-Fi module ESP8266, an SD card module and red, white and green LEDs. The white LED indicates that the cart is in standby mode or idle. The red LED indicates the reading of RFID tag numbers. The green LED indicates the generation of bill. The RFID reader reads the RFID tag numbers of tags attached to the product and transmits them over to the Arduino.

The Arduino is programmed using the Arduino software. In the program is declared a variable to which is appended the scanned RFID tag numbers with delimiter in between two number sequences. Once all the required items have been placed in the cart, the customer has to make use of an app previously downloaded to the mobile phone. When a HTTP GET request is made by the customer using the app, the ESP8266 Wi-Fi module is initiated and made to transmit the scanned tag numbers to the main server. The Wi-Fi module is basically used to enable the Arduino to connect to a Wi-Fi network, presuming that all supermarkets have a Wi-Fi network. Download now

B. The Billing and Gate Side System Descriptionnits

 The billing side system is coded using PHP. A socket (an end point between 2 communicating devices) is created and the data traffic of the ESP8266 Wi-Fi module on the cart is obtained using the socket. Each of the ESP8266 Wi-Fi module obtain an IP address from the Wi-Fi router which would beunique and that is how the server would know which cart is requesting the generation of the bill [3].Once the necessary items are purchased, the cart number is entered in the mobile app and the submit button is pressed.  

The app is developed using the MIT App Inventor. The app is designed in such a way that, on the click of submit button, based on the cart number, the app will be given access to the server (the computer) and the PHP codes for that particular cart will be run. The app is given access to server files by letting it know the IP of the server and the path of the file stored.Once the submit button is pressed, the customer is directed to an HTML form wherein the customer has to press the `Generate bill' button. Once this happens the data is received by the server from the ESP8266 Wi-Fi module and stored in a variable declared in the PHP program, the contents of the variable are broken down at places which contain the delimiter, which leads to the individual tag numbers. 

Then, the array_unique() function is made use of, in order to remove any repeated tag numbers which may have been a result of reading the same card multiple times, by the customer. Next, the individual tag numbers are stored in a text file wherein each line of the text file would contain the tag numbers. Next, each line of the text file is read and matched against a database which contains the RFID number, product ID, product name and its cost. If a match is found, then the corresponding details are retrieved and at the end all of the corresponding product costs are added to obtain the bill amount to be paid. The bill is displayed in the form of a table, below which there is a button in order to pay the bill.  https://codeshoppy.com/ Once the bill is paid for, the customer is sent an OTP that is generated randomly using the rand function in PHP. 

The gate side uses an Arduino interfaced with a servo motor, keypad, LCD and ESP8266 Wi-Fi module. The customer enters the OTP using the keypad, which is then displayed on the LCD. The Wi-Fi module also obtains the same OTP as the customer which is then used to verify if the OTP entered was correct. Once it has been verified, the gate opens 90 degrees vertically up from the initial horizontal position thereby letting the customer walk out of the store.