Circuit Documentation

Summary

The circuit in question is designed around the ESP8266 NodeMCU microcontroller, which serves as the central processing unit. The circuit includes a variety of peripherals, including a buzzer, red and green LEDs, an RFID-RC522 module, a fingerprint scanner, and an LCD Display with I2C interface. The purpose of the circuit is to create a security access system that uses RFID and fingerprint authentication to grant or deny access, with visual feedback provided by the LEDs and the LCD display, and auditory feedback provided by the buzzer.

Component List

ESP8266 NodeMCU

• Microcontroller with WiFi capability.
• Provides GPIO pins for interfacing with other components.

Buzzer

• An audible signaling device.

LED: Two Pin (red)

• A red light-emitting diode for visual indication.

LED: Two Pin (green)

• A green light-emitting diode for visual indication.

RFID-RC522

• An RFID reader/writer module for contactless communication using radio frequencies.

Fingerprint Scanner

• A biometric sensor for identifying individuals based on their fingerprints.

LCD Display 16x4 I2C

• An alphanumeric liquid crystal display with an I2C interface for displaying text.

Wiring Details

ESP8266 NodeMCU

• D0 connected to the anode of the red LED and the PIN of the buzzer.
• D1 connected to the SCL pin of the LCD Display.
• D2 connected to the SDA pin of the LCD Display.
• D3 connected to the RST pin of the RFID-RC522.
• D4 connected to the SDA pin of the RFID-RC522.
• D5 connected to the SCK pin of the RFID-RC522.
• D6 connected to the MISO pin of the RFID-RC522.
• D7 connected to the MOSI pin of the RFID-RC522.
• D8 connected to the anode of the green LED.
• RX connected to the TX pin of the Fingerprint Scanner.
• TX connected to the RX pin of the Fingerprint Scanner.
• GND connected to the GND pins of all components.
• 3V3 connected to the VCC (3.3V) pin of the RFID-RC522.

Buzzer

• PIN connected to D0 of the ESP8266 NodeMCU.
• GND connected to the common ground.

LED: Two Pin (red)

• anode connected to D0 of the ESP8266 NodeMCU.
• cathode connected to the common ground.

LED: Two Pin (green)

• anode connected to D8 of the ESP8266 NodeMCU.
• cathode connected to the common ground.

RFID-RC522

• VCC (3.3V) connected to 3V3 of the ESP8266 NodeMCU.
• RST connected to D3 of the ESP8266 NodeMCU.
• GND connected to the common ground.
• IRQ not connected.
• MISO connected to D6 of the ESP8266 NodeMCU.
• MOSI connected to D7 of the ESP8266 NodeMCU.
• SCK connected to D5 of the ESP8266 NodeMCU.
• SDA connected to D4 of the ESP8266 NodeMCU.

Fingerprint Scanner

• VCC not connected (assumed to be powered externally).
• TX connected to RX of the ESP8266 NodeMCU.
• RX connected to TX of the ESP8266 NodeMCU.
• GND connected to the common ground.

LCD Display 16x4 I2C

• SCL connected to D1 of the ESP8266 NodeMCU.
• SDA connected to D2 of the ESP8266 NodeMCU.
• VCC not connected (assumed to be powered externally).
• GND connected to the common ground.

Documented Code

#include <SPI.h>
#include <MFRC522.h>
#include <Adafruit_Fingerprint.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
#include <time.h>  // Include time library for NTP

// Define pins for RFID and peripherals
#define SS_PIN D4
#define RST_PIN D3
#define BUZZER_PIN D8
#define led D0
#define LCD_ADDRESS 0x27 // Define I2C address for LCD (typically 0x27 or 0x3F)

// Initialize the I2C LCD with address 0x27 and 20 columns x 4 rows
LiquidCrystal_I2C lcd(LCD_ADDRESS, 20, 4);

MFRC522 mfrc522(SS_PIN, RST_PIN);  // Create MFRC522 instance
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&Serial);  // Fingerprint sensor setup using hardware serial

// List of allowed RFID card UIDs with their associated fingerprint IDs, type, name, PC brand, and serial number
struct AllowedCard {
  byte uid[8];
  int type; // 0 = Student, 1 = Staff
  uint16_t fingerprintID; // Associated fingerprint ID
  String fullName; 
  String pcBrand; 
  String serialNumber; 
  String regNumber;  // Registration number (for students)
};

AllowedCard allowedCards[] = {
  {{0x73, 0xB5, 0xAE, 0x1A}, 0, 1, "Leon", "Dell", "SN123456", "REG123"},  // Student
  {{0xB3, 0xD0, 0x35, 0x42}, 1, 2, "Ngabo Robert", "HP", "SN654321", ""},   // Staff
  {{0x57, 0xC3, 0x5E, 0x86}, 0, 3, "Selemani", "Lenovo", "SN789012", "REG456"}  // Student
};

// WiFi credentials
const char* ssid = "Leon";
const char* password = "1234567890";
const char* serverUrl = "http://192.168.84.185/yourFolderName/uploadData.php";  // Replace with your local server address

// NTP Server
const char* ntpServer = "pool.ntp.org";
const long gmtOffset_sec = 3600;  // Offset for your timezone, e.g., +1 hour (GMT+1)
const int daylightOffset_sec = 3600;  // Daylight saving offset (if applicable)

// Variable to track Sign-In/Sign-Out
String signStatus = "Sign-In";

void setup() {
  Serial.begin(57600);  
  finger.begin(57600); // Start fingerprint sensor
  SPI.begin();        // Init SPI bus
  mfrc522.PCD_Init(); // Init MFRC522

  pinMode(BUZZER_PIN, OUTPUT);
  lcd.begin();
  lcd.backlight(); // Turn on the backlight
  lcd.setCursor(0, 0);
  lcd.print("RFID Reader Ready");

  if (finger.verifyPassword()) {
    lcd.setCursor(0, 1);
    lcd.print("Fingerprint Ready");
  } else {
    lcd.setCursor(0, 1);
    lcd.print("Fingerprint Error");
    while (1);
  }

  connectToWiFi();
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);  // Initialize NTP time synchronization

  Serial.println("RFID Reader Initialized.");
  Serial.println("Tap your card to begin...");
}

void loop() {
  // Rest of the code...
}

// Additional functions...

The code provided is a partial listing, focusing on the setup and initialization of the components. It includes the setup of the RFID reader, fingerprint scanner, LCD display, and WiFi connection. The loop function and additional utility functions are implied to handle the main logic of the access control system, including reading RFID tags, verifying fingerprints, and communicating with a server.