Mini Project 1

RFID RC522 Module (SPI)

RFID Pin	Arduino Pin
SDA (SS)	10
SCK	13
MOSI	11
MISO	12
GND	GND
RST	9
3.3V	3.3V

16x2 LCD (Using 4-bit Mode)

LCD Pin	New Arduino Pin
VSS	GND
VDD	5V
V0	(Potentiometer - Contrast Control)
RS	7
RW	GND
E (Enable)	6
D4	5
D5	4
D6	3
D7	2
A	5V
K	GND

#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal.h>

#define SS_PIN 10
#define RST_PIN 9

MFRC522 mfrc522(SS_PIN, RST_PIN);

// Initialize the LCD with new separate pins
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

void setup() {
  Serial.begin(9600);
  Serial.println("System Initialized");

  SPI.begin();
  mfrc522.PCD_Init();

  lcd.begin(16, 2);
  lcd.print("Place your card");
  Serial.println("Waiting for card...");
}

void loop() {
  if (!mfrc522.PICC_IsNewCardPresent() || !mfrc522.PICC_ReadCardSerial()) {
    return;
  }

  Serial.println("Card detected!");

  // Clear the LCD and prepare to display the UID
  lcd.clear();
  lcd.print("UID: ");

  Serial.print("UID tag: ");
  String uidString = "";

  for (byte i = 0; i < mfrc522.uid.size; i++) {
    // Convert byte to HEX without spaces
    if (mfrc522.uid.uidByte[i] < 0x10) {
      uidString += "0";  // Add leading zero for single-digit hex values
    }
    uidString += String(mfrc522.uid.uidByte[i], HEX);
  }

  // Convert to uppercase for better readability
  uidString.toUpperCase();

  // Print UID to Serial Monitor and LCD
  Serial.println(uidString);
  lcd.print(uidString);

  Serial.println("UID displayed on LCD.");

  mfrc522.PICC_HaltA();
  Serial.println("Waiting for next card...");
}