/*
 * ----------------------------------------------------------------------
 * Example program showing how to read new NUID from a PICC to serial.
 * ----------------------------------------------------------------------
 * 
 * RC522 Interfacing with NodeMCU
 * 
 * Typical pin layout used:
 * ----------------------------------
 *             MFRC522      Node     
 *             Reader/PCD   MCU      
 * Signal      Pin          Pin      
 * ----------------------------------
 * RST/Reset   RST          D1 (GPIO5)        
 * SPI SS      SDA(SS)      D2 (GPIO4)       
 * SPI MOSI    MOSI         D7 (GPIO13)
 * SPI MISO    MISO         D6 (GPIO12)
 * SPI SCK     SCK          D5 (GPIO14)
 * 3.3V        3.3V         3.3V
 * GND         GND          GND
 */

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

constexpr uint8_t RST_PIN = 5;     // Configurable, see typical pin layout above
constexpr uint8_t SS_PIN = 4;     // Configurable, see typical pin layout above
MFRC522 rfid(SS_PIN, RST_PIN); // Instance of the class
MFRC522::MIFARE_Key key; 
String card_id;



void setup() { 
  Serial.begin(115200);
  //========rfid
  SPI.begin(); // Init SPI bus
  rfid_init();
  //========
}
 
void loop() 
{
	if(read_rfid()!="")
	{
		Serial.print("card id: ");
		Serial.println(card_id);
	}
	else
	{
		return;
	}
		

}

//==============================================================RFID FUNCTIONS
void rfid_init()
{
	rfid.PCD_Init(); // Init MFRC522 
	for (byte i = 0; i < 6; i++) {
		key.keyByte[i] = 0xFF;
	}
}

String read_rfid()
{
	// Look for new cards
	if ( ! rfid.PICC_IsNewCardPresent())
		return "";

	// Verify if the NUID has been readed
	if ( ! rfid.PICC_ReadCardSerial())
		return "";

	//-------------------PICC_TYPE
	MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak);
	String PICC_TYPE=rfid.PICC_GetTypeName(piccType);
	//Serial.println(PICC_TYPE);
	//--------------------
	
	
	// Check is the PICC of Classic MIFARE type
	if (piccType != MFRC522::PICC_TYPE_MIFARE_MINI &&  
	piccType != MFRC522::PICC_TYPE_MIFARE_1K &&
	piccType != MFRC522::PICC_TYPE_MIFARE_4K) 
	{
		return "ERR-CARD-TYPE";//Your tag is not of type MIFARE Classic.
	}

	card_id=get_card_id(rfid.uid.uidByte, rfid.uid.size);
	

	// Halt PICC
	rfid.PICC_HaltA();

	// Stop encryption on PCD
	rfid.PCD_StopCrypto1();
	
	return card_id;
  
}


String get_card_id(byte *buffer, byte bufferSize) {
	String temp_card_id="";
	for (byte i = 0; i < bufferSize; i++) 
	{
		if(buffer[i] < 0x10) 
			if(i==0)
				temp_card_id=+"0"; 
			else
				temp_card_id=+" 0";
		else 
			if(i!=0)
				temp_card_id+=" ";

		
		temp_card_id+=String(buffer[i]);
	}
	return temp_card_id;
}
//==============================================================