/*
 * This ESP32 code is created by esp32io.com
 *
 * This ESP32 code is released in the public domain
 *
 * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-rfid-nfc
 */
 #include <Arduino.h>
 #include <SPI.h>
 #include <MFRC522.h>
 
 #define SS_PIN  5  // ESP32 pin GPIO5 
 #define RST_PIN 27 // ESP32 pin GPIO27 
 
 MFRC522 rfid(SS_PIN, RST_PIN);
 
 void setup() {
   Serial.begin(115200);
   SPI.begin(); // init SPI bus
   rfid.PCD_Init(); // init MFRC522
   rfid.PCD_DumpVersionToSerial(); // Dump the firmware version
 
   Serial.println("Tap an RFID/NFC tag on the RFID-RC522 reader");

   Serial.print("stage1");
   
 }
 
void loop() {
  // Reset the loop if no new card is present
  if (!rfid.PICC_IsNewCardPresent()) {
    return;
  }

  // Select a card and read its UID
  if (!rfid.PICC_ReadCardSerial()) {
    return;
  }

  // Print UID in Serial Monitor in hex format
  Serial.print("UID:");
  for (int i = 0; i < rfid.uid.size; i++) {
    Serial.print(rfid.uid.uidByte[i] < 0x10 ? " 0" : " ");
    Serial.print(rfid.uid.uidByte[i], HEX);
  }
  Serial.println();

  // Halt PICC and stop encryption
  rfid.PICC_HaltA();
  rfid.PCD_StopCrypto1();

  delay(1000); // Optional: slow down the loop for readability
}