Project Documentation

Arduino and ESP8266-Based RFID Access Control System with Real-Time Firebase Logging

Circuit Documentation

Summary

This circuit is an RFID-based access control system. It uses an Arduino UNO to interface with an RFID reader, a servo motor, a buzzer, an RTC module, an I2C LCD, and an ESP8266 NodeMCU for Wi-Fi connectivity. The system reads RFID tags, checks for authorized access, and logs access attempts to a Firebase database via the ESP8266.

Component List

Arduino UNO
- Description: Microcontroller board based on the ATmega328P.
- Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0
RFID-RC522
- Description: RFID reader module.
- Pins: VCC (3.3V), RST, GND, IRQ, MISO, MOSI, SCK, SDA
Buzzer
- Description: Simple piezoelectric buzzer.
- Pins: PIN, GND
RTC
- Description: Real-Time Clock module.
- Pins: VCC, GND, CLK, DAT, RST
Servo
- Description: Servo motor for mechanical movement.
- Pins: GND, VCC, PWM
16x2 I2C LCD
- Description: 16x2 character LCD with I2C interface.
- Pins: GND, VCC, SDA, SCL
ESP8266 NodeMCU
- Description: Wi-Fi module for internet connectivity.
- Pins: D0, D1, D2, D3, D4, 3V3, GND, D5, D6, D7, D8, RX, TX, A0, RSV, SD3, SD2, SD1, CMD, SD0, CLK, EN, RST, VIN
LED: Two Pin (red)
- Description: Red LED.
- Pins: cathode, anode
Resistor (200 Ohms)
- Description: Resistor with 200 Ohms resistance.
- Pins: pin1, pin2
LED: Two Pin (green)
- Description: Green LED.
- Pins: cathode, anode

Wiring Details

Arduino UNO

A4: Connected to RTC (CLK) and 16x2 I2C LCD (SDA)
A5: Connected to RTC (DAT) and 16x2 I2C LCD (SCL)
5V: Connected to RTC (VCC), RFID-RC522 (VCC), Servo (VCC), and 16x2 I2C LCD (VCC)
GND: Connected to RTC (GND), RFID-RC522 (GND), Servo (GND), LED (red) (anode), LED (green) (anode), Buzzer (GND)
D13: Connected to RFID-RC522 (MOSI)
D12: Connected to RFID-RC522 (MISO)
D11: Connected to RFID-RC522 (SCK)
D7: Connected to Resistor (pin2)
D6: Connected to Resistor (pin1)
D5: Connected to Buzzer (PIN)
D4: Connected to Servo (PWM)
D3: Connected to RFID-RC522 (RST)
D2: Connected to RTC (RST)
D1: Connected to ESP8266 NodeMCU (D2)
D0: Connected to ESP8266 NodeMCU (D3)

RFID-RC522

VCC (3.3V): Connected to Arduino UNO (5V)
RST: Connected to Arduino UNO (D3)
GND: Connected to Arduino UNO (GND)
MISO: Connected to Arduino UNO (D12)
MOSI: Connected to Arduino UNO (D13)
SCK: Connected to Arduino UNO (D11)
SDA: Not connected

Buzzer

PIN: Connected to Arduino UNO (D5)
GND: Connected to Arduino UNO (GND)

RTC

VCC: Connected to Arduino UNO (5V)
GND: Connected to Arduino UNO (GND)
CLK: Connected to Arduino UNO (A4)
DAT: Connected to Arduino UNO (A5)
RST: Connected to Arduino UNO (D2)

Servo

GND: Connected to Arduino UNO (GND)
VCC: Connected to Arduino UNO (5V)
PWM: Connected to Arduino UNO (D4)

16x2 I2C LCD

GND: Connected to Arduino UNO (GND)
VCC: Connected to Arduino UNO (5V)
SDA: Connected to Arduino UNO (A4)
SCL: Connected to Arduino UNO (A5)

ESP8266 NodeMCU

D2: Connected to Arduino UNO (D1)
D3: Connected to Arduino UNO (D0)

LED: Two Pin (red)

cathode: Connected to Resistor (pin2)
anode: Connected to Arduino UNO (GND)

Resistor (200 Ohms)

pin1: Connected to Arduino UNO (D6)
pin2: Connected to LED (red) (cathode)

LED: Two Pin (green)

cathode: Connected to Resistor (pin1)
anode: Connected to Arduino UNO (GND)

Code Documentation

Arduino UNO Code

#include <Wire.h>
#include <LiquidCrystal_PCF8574.h>
#include <SPI.h>
#include <MFRC522.h>
#include <Servo.h>

// Define the I2C address for the LCD
#define LCD_ADDRESS 0x27

// RFID Module Pins
#define RFID_PIN_RST 9
#define RFID_PIN_SDA 10

// Buzzer Pin
#define BUZZER_PIN 2

// Servo Pin
#define SERVO_PIN 4

// Authorized UID
const String authorizedUID = "608ACD21";

// Create objects for peripherals
LiquidCrystal_PCF8574 lcd(LCD_ADDRESS);
MFRC522 rfid(RFID_PIN_SDA, RFID_PIN_RST);
Servo servo;

void setup() {
  Serial.begin(9600);

  lcd.begin(16, 2);
  lcd.setBacklight(255);
  lcd.clear();
  lcd.print("Scan your tag...");

  SPI.begin();
  rfid.PCD_Init();

  pinMode(BUZZER_PIN, OUTPUT);
  servo.attach(SERVO_PIN);
  servo.write(0);
}

void loop() {
  handleRFID();
}

void handleRFID() {
  if (!rfid.PICC_IsNewCardPresent() || !rfid.PICC_ReadCardSerial()) {
    return; // No card found
  }

  // Read the UID
  String scannedUID = "";
  for (byte i = 0; i < rfid.uid.size; i++) {
    scannedUID += String(rfid.uid.uidByte[i], HEX);
  }
  scannedUID.toUpperCase();

  lcd.clear();
  String accessStatus;
  if (scannedUID == authorizedUID) {
    lcd.print("Access Granted");
    servo.write(180);
    tone(BUZZER_PIN, 1000);
    delay(500);
    noTone(BUZZER_PIN);
    delay(3000);
    servo.write(0);
    accessStatus = "Granted";
  } else {
    lcd.print("Access Denied");
    for (int i = 0; i < 2; i++) {
      tone(BUZZER_PIN, 1000);
      delay(300);
      noTone(BUZZER_PIN);
      delay(300);
    }
    accessStatus = "Denied";
  }

  // Send UID, access status, and timestamp to ESP8266
  unsigned long timestamp = millis();
  Serial.println(scannedUID + ":" + accessStatus + ":" + String(timestamp));

  delay(500); // Small delay for stability
  lcd.clear();
  lcd.print("Scan your tag...");
  rfid.PICC_HaltA();       // Halt PICC communication
  rfid.PCD_StopCrypto1();  // Stop encryption
}

ESP8266 NodeMCU Code

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <Firebase_ESP_Client.h>
#include "addons/TokenHelper.h"
#include "addons/RTDBHelper.h"
#include <SoftwareSerial.h>

// Wi-Fi credentials
#define WIFI_SSID "IT Club"
#define WIFI_PASSWORD "#9]BF4crc1"

// Firebase credentials
#define API_KEY "AIza