We took the case of our hostel mess and concluded that there is no proper way to manage the hostel mess. There we came up with a solution to use a biometric attendance system to monitor the mess. Every time a student goes to take food they are required to punch on the biometric scanner to register that he/she has taken the item. This will efficiently allow us to monitor the number of times a person has taken the mess in a week/month and allows us to calculate his monthly bill accordingly. We have also developed a Webpage with a cloud-based backup with google cloud working in the backend so that he/she can view your monthly expenses at any point in time from anywhere.

Problem statement

Our college hostels have no proper attendance-taking system for mess management even though most of our students are staying in hostels. Currently, it is done manually with a register which is a tedious and repetitive task where many errors can arise and which cause problems when the admin publishes the attendance list. Proper attendance taking is important for the smooth working of the mess and it will also help to improve the total efficiency in the manner of both money and time. We devised a solution to use a biometric attendance system to monitor the mess. Every time a student goes to take food they are required to punch on the biometric scanner to register that he/she has taken the item.

Having an efficient attendance system for the hostel mess is one of the main requirements for its smooth and proper operation. In the case of our hostels, we always felt the need for a proper attendance management system. So our aim was to solve that problem with an efficient system so we came up with a solution to use a biometric attendance system to monitor the mess. Every time a student goes to take food they are required to punch on the biometric scanner to register that he/she has taken the item. This will efficiently allow us to monitor the number of times a person has taken food in a day and allows us to calculate his monthly bill accordingly. We have also developed a Webpage with a cloud-based backup with google cloud in the backend so that he/she can view their monthly attendance and calculated expenses at any point from anywhere and admins can manage the inmates more effectively. Also, the same product can be used in many other cases such as to mark the presence in offices and schools. This project has a wide application in schools, colleges, business organizations, and offices where marking of attendance is required accurately with time. By using the fingerprint sensor, the system will become more secure for the users.

Hardware Software used in building the ADFS are:

Hardware

• ESP32 - NodeMCU
• Finger Print Scanner Module - R307 module.
• OLED Display
• Li-ion Battery
• Battery Charger

Software

• Arduino IDE
• React JS
• Firebase

CAD Design

Step 1: Design and construct the circuit (Follow the figure below )

Step 2: Solder the components and attach the circuit to the chassis

Step 3: Attach the button to the circuit and chassis

Step 4: Connect the battery and charger module to the enclosure

How to use it?

Step1: Install the Adafruit fingerprint library and upload the enrollment code

First, install and set up Arduino IDE for coding ESP32. You can follow this tutorial - https://randomnerdtutorials.com/installing-the-esp32-board-in-arduino-ide-windows-instructions/

Then search 'fingerprint' on the Arduino IDE Library manager and install the Adafruit fingerprint library. Then from open > libraries > Adafruti_Fingerprint_Sensor_Library > enroll. To enrol new fingerprint templates to the fingerprint sensor's onboard database. (Which can store up to 200 fingerprints)

/*************************************************** This is an example sketch for our optical Fingerprint sensor Designed specifically to work with the Adafruit BMP085 Breakout ----> http://www.adafruit.com/products/751 These displays use TTL Serial to communicate, 2 pins are required to interface Adafruit invests time and resources providing this open source code, please support Adafruit and open-source hardware by purchasing products from Adafruit! Written by Limor Fried/Ladyada for Adafruit Industries. BSD license, all text above must be included in any redistribution ****************************************************/ #include <Adafruit_Fingerprint.h> #if (defined(__AVR__) || defined(ESP8266)) && !defined(__AVR_ATmega2560__) // For UNO and others without hardware serial, we must use software serial... // pin #2 is IN from sensor (GREEN wire) // pin #3 is OUT from arduino (WHITE wire) // Set up the serial port to use softwareserial.. // SoftwareSerial mySerial(16, 17); #else // On Leonardo/M0/etc, others with hardware serial, use hardware serial! // #0 is green wire, #1 is white #define mySerial Serial2 #endif Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial); uint8_t id; void setup() { Serial.begin(9600); while (!Serial); // For Yun/Leo/Micro/Zero/... delay(100); Serial.println("\n\nAdafruit Fingerprint sensor enrollment"); // set the data rate for the sensor serial port finger.begin(57600); if (finger.verifyPassword()) {  Serial.println("Found fingerprint sensor!"); } else {  Serial.println("Did not find fingerprint sensor :(");  while (1) { delay(1); } } Serial.println(F("Reading sensor parameters")); finger.getParameters(); Serial.print(F("Status: 0x")); Serial.println(finger.status_reg, HEX); Serial.print(F("Sys ID: 0x")); Serial.println(finger.system_id, HEX); Serial.print(F("Capacity: ")); Serial.println(finger.capacity); Serial.print(F("Security level: ")); Serial.println(finger.security_level); Serial.print(F("Device address: ")); Serial.println(finger.device_addr, HEX); Serial.print(F("Packet len: ")); Serial.println(finger.packet_len); Serial.print(F("Baud rate: ")); Serial.println(finger.baud_rate); } uint8_t readnumber(void) { uint8_t num = 0; while (num == 0) {  while (! Serial.available());  num = Serial.parseInt(); } return num; } void loop()           // run over and over again { Serial.println("Ready to enroll a fingerprint!"); Serial.println("Please type in the ID # (from 1 to 127) you want to save this finger as..."); id = readnumber(); if (id == 0) {// ID #0 not allowed, try again!   return; } Serial.print("Enrolling ID #"); Serial.println(id); while (! getFingerprintEnroll() ); } uint8_t getFingerprintEnroll() { int p = -1; Serial.print("Waiting for valid finger to enroll as #"); Serial.println(id); while (p != FINGERPRINT_OK) {  p = finger.getImage();  switch (p) {  case FINGERPRINT_OK:   Serial.println("Image taken");   break;  case FINGERPRINT_NOFINGER:   Serial.println(".");   break;  case FINGERPRINT_PACKETRECIEVEERR:   Serial.println("Communication error");   break;  case FINGERPRINT_IMAGEFAIL:   Serial.println("Imaging error");   break;  default:   Serial.println("Unknown error");   break;  } } // OK success! p = finger.image2Tz(1); switch (p) {  case FINGERPRINT_OK:   Serial.println("Image converted");   break;  case FINGERPRINT_IMAGEMESS:   Serial.println("Image too messy");   return p;  case FINGERPRINT_PACKETRECIEVEERR:   Serial.println("Communication error");   return p;  case FINGERPRINT_FEATUREFAIL:   Serial.println("Could not find fingerprint features");   return p;  case FINGERPRINT_INVALIDIMAGE:   Serial.println("Could not find fingerprint features");   return p;  default:   Serial.println("Unknown error");   return p; } Serial.println("Remove finger"); delay(2000); p = 0; while (p != FINGERPRINT_NOFINGER) {  p = finger.getImage(); } Serial.print("ID "); Serial.println(id); p = -1; Serial.println("Place same finger again"); while (p != FINGERPRINT_OK) {  p = finger.getImage();  switch (p) {  case FINGERPRINT_OK:   Serial.println("Image taken");   break;  case FINGERPRINT_NOFINGER:   Serial.print(".");   break;  case FINGERPRINT_PACKETRECIEVEERR:   Serial.println("Communication error");   break;  case FINGERPRINT_IMAGEFAIL:   Serial.println("Imaging error");   break;  default:   Serial.println("Unknown error");   break;  } } // OK success! p = finger.image2Tz(2); switch (p) {  case FINGERPRINT_OK:   Serial.println("Image converted");   break;  case FINGERPRINT_IMAGEMESS:   Serial.println("Image too messy");   return p;  case FINGERPRINT_PACKETRECIEVEERR:   Serial.println("Communication error");   return p;  case FINGERPRINT_FEATUREFAIL:   Serial.println("Could not find fingerprint features");   return p;  case FINGERPRINT_INVALIDIMAGE:   Serial.println("Could not find fingerprint features");   return p;  default:   Serial.println("Unknown error");   return p; } // OK converted! Serial.print("Creating model for #"); Serial.println(id); p = finger.createModel(); if (p == FINGERPRINT_OK) {  Serial.println("Prints matched!"); } else if (p == FINGERPRINT_PACKETRECIEVEERR) {  Serial.println("Communication error");  return p; } else if (p == FINGERPRINT_ENROLLMISMATCH) {  Serial.println("Fingerprints did not match");  return p; } else {  Serial.println("Unknown error");  return p; } Serial.print("ID "); Serial.println(id); p = finger.storeModel(id); if (p == FINGERPRINT_OK) {  Serial.println("Stored!"); } else if (p == FINGERPRINT_PACKETRECIEVEERR) {  Serial.println("Communication error");  return p; } else if (p == FINGERPRINT_BADLOCATION) {  Serial.println("Could not store in that location");  return p; } else if (p == FINGERPRINT_FLASHERR) {  Serial.println("Error writing to flash");  return p; } else {  Serial.println("Unknown error");  return p; } return true; }

Note down the name and assigned fingerprint ids of each person u are enrolling. Which will be used in the next step.

Step2: Create a firebase project and get your client ID

Open the project and add authentication to the project and click to add a new user

Then type an email and password (Which should not be needed to be a real email address but note down the password). This will be used later as the authentication information of the device.

A new user will be created and a unique id will be automatically assigned to it as shown below. We want to use this too later.

Now add the real-time database to the project.

And add the fields to store the information of the device.

Under biometricScanners > UID > data > add the names and corresponding fingerprint template id that is created during enrollment as shown below.

Step3: Create the WebApp to view the updates

https://github.com/mohdazharsm/ABFS_Web_App you can clone this repository and follow the instructions below to setup the web app. (Learn how to set up React project and install all pre-requisites)

1. First, open the terminal in the project directory and run the command npm install

2. Go to firebase console > Project setting and copy the project credentials

3. Then paste it to config.js inside the firebase folder in the project directory.

4. Then create a Firestore database in the firebase project console and create a collection named "institutions" After, that create the document with an id for the institutions, which is to be listed on the registration page (You can create more than one institution).

5. Then add another collection named "biometricscanners" and inside that create the document with the document name of the UID of the device (created in the previous step) and add the fields as shown. (Must add the admin field and list the emails that are going to register as users in the next step to view the device data, the device's detail will only be displayed to the admin users)

The "users" collection will be automatically created when the user is registered as shown in the next step.

5. Now run the Webapp using the command npm start to launch the website in localhost. and register. (The email id of the google account used to register should be the same as in the admin list to view the device data)

6. Now upload the final code to the device

//Fingerprint sensor #include <Adafruit_Fingerprint.h> #define mySerial Serial2 Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial); //OLED #include <Wire.h> #include <Adafruit_GFX.h> #include <Adafruit_SSD1306.h> #define SCREEN_WIDTH 128 // OLED display width, in pixels #define SCREEN_HEIGHT 64 // OLED display height, in pixels Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1); static const unsigned char PROGMEM logo_bmp[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0xff, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0xff, 0x83, 0xff, 0xc0, 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0xfe, 0x7c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x1f, 0x1e, 0x3e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0e, 0x3e, 0x0f, 0x1e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3c, 0x0f, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; //WIFI #include <Arduino.h> #include <WiFi.h> // Insert your network credentials #define WIFI_SSID "ssid" #define WIFI_PASSWORD "password" //Firebase #include <Firebase_ESP_Client.h> //Provide the token generation process info. #include "addons/TokenHelper.h" //Provide the RTDB payload printing info and other helper functions. #include "addons/RTDBHelper.h" // Insert Firebase project API Key #define API_KEY "YOUR_ API_KEY" /* 3. Define the user Email and password that already registerd or added in your project */ #define USER_EMAIL "device_email_oid" #define USER_PASSWORD "device_password" // Insert RTDB URLefine the RTDB URL */ #define DATABASE_URL "https://abfs-83be0-default-rtdb.asia-southeast1.firebasedatabase.app/"  //Define Firebase Data object FirebaseData fbdo; FirebaseAuth auth; FirebaseConfig config; // RGB LED #include <FastLED.h> #define LED_PIN   21 #define NUM_LEDS  1 CRGB leds[NUM_LEDS]; void setup() { Serial.begin(9600); delay(100); Serial.println("\n\nABFS Starting.."); // RGB LED FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS); leds[0] = CRGB(255, 255, 255); FastLED.show(); delay(100); //Display Wire.begin(33, 32); if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64  Serial.println(F("SSD1306 allocation failed"));  for(;;); } delay(1000);   printDisplay("Starting.."); //WIFI WiFi.begin(WIFI_SSID, WIFI_PASSWORD); Serial.print("Connecting to Wi-Fi"); printDisplay("Connecting WIFI..."); while (WiFi.status() != WL_CONNECTED){  Serial.print(".");  delay(300); } Serial.println(); Serial.print("Connected with IP: "); Serial.println(WiFi.localIP()); Serial.println(); /* Assign the api key (required) */ config.api_key = API_KEY; /* Assign the user sign in credentials */ auth.user.email = USER_EMAIL; auth.user.password = USER_PASSWORD; /* Assign the RTDB URL (required) */ config.database_url = DATABASE_URL; /* Assign the callback function for the long running token generation task */ config.token_status_callback = tokenStatusCallback; //see addons/TokenHelper.h Firebase.begin(&config, &auth); Firebase.reconnectWiFi(true); // Fingerprint sensor // set the data rate for the sensor serial port finger.begin(57600); delay(5);   if (finger.verifyPassword()) {  Serial.println("Found fingerprint sensor!");  printDisplay("Sensor Ready"); } else {  Serial.println("Did not find fingerprint sensor :(");  while (1) { delay(1); } } finger.getTemplateCount(); if (finger.templateCount == 0) {  Serial.print("Sensor doesn't contain any fingerprint data. Please run the 'enroll' example."); } else {  Serial.println("Waiting for valid finger...");  Serial.print("Sensor contains "); Serial.print(finger.templateCount); Serial.println(" templates");  String countString = "Fingers: ";  countString += finger.templateCount;  printDisplay(countString);  delay(1000);  fingerScanDisplay(); } } int fingerID; unsigned long lastSeenSetMillis = 0; String fStatus = ""; void loop() {  if (Firebase.ready()){  fingerID = getFingerprintIDez();  //Firebase  String uid = auth.token.uid.c_str(); //uid of the device     if(fingerID==-2){   // RGB led   leds[0] = CRGB(255, 0, 0);   FastLED.show();   //Firebase   sendLastSeenAndStatusTofirebase(uid, "User not enrolled");  }  else if(fingerID!=-1){   // RGB led   leds[0] = CRGB(0, 255, 0);   FastLED.show();       //Firebase   sendAttendanceTofirebase(uid, fingerID);   String nameOfId = getNameFromFId(uid, fingerID);       //Display   nameDisplay(nameOfId);   Serial.println(nameOfId);   //Firebase   sendLastSeenAndStatusTofirebase(uid, "User verified");       delay(1000);  } else {   // RGB led   leds[0] = CRGB(0, 0, 255);   FastLED.show();   //Display   fingerScanDisplay();   //Firebase   sendLastSeenAndStatusTofirebase(uid, "Waiting for user");  }  delay(50); } else {  printDisplay("Not connected to server"); } } void sendAttendanceTofirebase(String uid, int value) {      String path = "/attendance/";   path += uid;      String timestampPath = path;   path += "/id";   timestampPath += "/time";  // Write an Int number on the database path test/int  if (Firebase.RTDB.setInt(&fbdo, path, value) && Firebase.RTDB.setTimestamp(&fbdo, timestampPath)){   Serial.println("PASSED");   Serial.println("PATH: " + fbdo.dataPath());   Serial.println("TYPE: " + fbdo.dataType());  }  else {   Serial.println("FAILED");   Serial.println("REASON: " + fbdo.errorReason());  } } void sendLastSeenAndStatusTofirebase(String uid, String value) {  if(value!=fStatus || (millis() - lastSeenSetMillis > 60000 || lastSeenSetMillis == 0)){      fStatus = value;     lastSeenSetMillis = millis();        String path = "/biometricScanners/";   path += uid;   String timestampPath = path;   path += "/status";   timestampPath += "/lastSeen";   // Write an Int number on the database path test/int   if((value=="" || Firebase.RTDB.setString(&fbdo, path, value)) && Firebase.RTDB.setTimestamp(&fbdo, timestampPath)){   Serial.println("PASSED");   Serial.println("PATH: " + fbdo.dataPath());   Serial.println("TYPE: " + fbdo.dataType());  }  else {   Serial.println("FAILED");   Serial.println("REASON: " + fbdo.errorReason());  } } } // returns -1 if failed, otherwise returns ID # int getFingerprintIDez() { uint8_t p = finger.getImage(); if (p != FINGERPRINT_OK) return -1; p = finger.image2Tz(); if (p != FINGERPRINT_OK) return -1; p = finger.fingerFastSearch(); if (p == FINGERPRINT_NOTFOUND) return -2; if (p != FINGERPRINT_OK) return -1; // found a match! Serial.print("Found ID #"); Serial.print(finger.fingerID); Serial.print(" with confidence of "); Serial.println(finger.confidence); return finger.fingerID; } String getNameFromFId(String uid, int fingerID){ String path = "/biometricScanners/"; path += uid; path += "/data/"; path += fingerID;   if (Firebase.RTDB.getString(&fbdo, path)) {  Serial.println("PATH: " + fbdo.dataPath());  return fbdo.to<const char *>(); } else {  Serial.println("PATH: " + fbdo.dataPath());  Serial.println(fbdo.errorReason());  return "Error"; } } void printDisplay(String value){  display.clearDisplay();  display.setTextSize(2);  display.setTextColor(WHITE);  display.setCursor(0,25);  display.println(value);  display.display();  } void nameDisplay(String value){  display.clearDisplay();  display.setTextSize(2);  display.setTextColor(WHITE);  display.setCursor(14,0);  display.println("Welcome");  display.setTextSize(2);  display.setTextColor(WHITE);  display.setCursor(0,25);  display.println(value);  display.display();  } void fingerScanDisplay(){  display.clearDisplay();  display.drawBitmap(0, 0, logo_bmp, SCREEN_WIDTH, SCREEN_HEIGHT, 1);  display.display(); }

Now turn on the device to see the online/offline status

When the device is ready to use, touch the fingerprint sensor to see the attendance of the user if already enrolled.

The Final State Of The Project