NodeMCU Mifare MFRC522 RFID Reader/Writer

/*
Many thanks to nikxha from the ESP8266 forum
*/

#include <ESP8266WiFi.h>
#include <SPI.h>
#include "MFRC522.h"

/* Wiring RFID RC522 module
=============================================================================
GND     = GND   3.3V    = 3.3V
The following table shows the typical pin layout used:
Signal        MFRC522     WeMos D1 mini     NodeMcu     Generic
RST/Reset     RST         D3 [1]            D3 [1]      GPIO-0 [1]
SPI SS        SDA [3]     D8 [2]            D8 [2]      GPIO-15 [2]
SPI MOSI      MOSI        D7                D7          GPIO-13
SPI MISO      MISO        D6                D6          GPIO-12
SPI SCK       SCK         D5                D5          GPIO-14
[1] (1, 2) Configurable, typically defined as RST_PIN in sketch/program.
[2] (1, 2) Configurable, typically defined as SS_PIN in sketch/program.
[3] The SDA pin might be labeled SS on some/older MFRC522 boards
=============================================================================
*/

#define RST_PIN  D3     // RST-PIN für RC522 - RFID - SPI - D3
#define SS_PIN   D8     // SDA-PIN für RC522 - RFID - SPI - D8

// Update these with values suitable for your network.
//const char *ssid = "PTS-2F";
//const char *pass = "";
const char *ssid = "74170287";
const char *pass = "24063173";
//const char *ssid =  "yourSSID";     // change according to your Network - cannot be longer than 32 characters!
//const char *pass =  "yourPASSWORD"; // change according to your Network

MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance

//Variables
long lastMsg = 0;
String IDNo_buf="";
//=============================================================================
void setup() {
  Serial.begin(115200);    // Initialize serial communications
  delay(250);
  Serial.println(F("Booting...."));
 
  SPI.begin();           // Init SPI bus
  mfrc522.PCD_Init();    // Init MFRC522
 
  WiFi.begin(ssid, pass);
 
  int retries = 0;
  while ((WiFi.status() != WL_CONNECTED) && (retries < 10)) {
    retries++;
    delay(500);
    Serial.print(".");
  }
  if (WiFi.status() == WL_CONNECTED) {
    Serial.println(F("WiFi connected"));
  }
 
  Serial.println(F("Ready!"));
  Serial.println(F("======================================================"));
  Serial.println(F("Scan for Card and print UID:"));
}
//=============================================================================
void loop() {
  // Look for new cards
  /*if ( ! mfrc522.PICC_IsNewCardPresent()) {
    delay(50);
    return;
  }
  // Select one of the cards
  if ( ! mfrc522.PICC_ReadCardSerial()) {
    delay(50);
    return;
  }*/
 
  long now = millis();
  // 確認是否有新卡片
  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) { // 如果出現新卡片就讀取卡片資料
     delay(100);
     String IDNo = printHex(mfrc522.uid.uidByte, mfrc522.uid.size);
     // Show some details of the PICC (that is: the tag/card)
     if ((IDNo != IDNo_buf) || (now - lastMsg > 5000)) {
         lastMsg = now;
         Serial.print(F("Card UID:"));
         Serial.println(IDNo);
         //Serial.println(IDNo_buf);
   
         IDNo_buf="";
         IDNo_buf=IDNo;
       }
 
  //Serial.print(F("Card UID:"));
  //dump_byte_array_dec(mfrc522.uid.uidByte, mfrc522.uid.size);
  //dump_byte_array(mfrc522.uid.uidByte, mfrc522.uid.size);
  //Serial.println();
  }
}
//=============================================================================
String printHex(byte *buffer, byte bufferSize) {
      String id = "";
      for (byte i = 0; i < bufferSize; i++) {
        id += buffer[i] < 0x10 ? "0" : "";
        id += String(buffer[i], HEX);
      }
      return id;
    }

//=============================================================================
/*
// Helper routine to dump a byte array as hex values to Serial
void dump_byte_array(byte *buffer, byte bufferSize) {
  for (byte i = 0; i < bufferSize; i++) {
    Serial.print(buffer[i] < 0x10 ? " 0" : " ");
    Serial.print(buffer[i], HEX);
  }
}
//=============================================================================
// Helper routine to dump a byte array as hex values to Serial
void dump_byte_array_dec(byte *buffer, byte bufferSize) {
  for (byte i = 0; i < bufferSize; i++) {
    Serial.print(buffer[i] < 0x10 ? " 0" : " ");
    Serial.print(buffer[i], DEC);
  }
}
//=============================================================================
*/