Added node dtdns updater

C++/Arduino/RFID_Reader_Writer/RFID_Reader_Writer.ino

@@ -10,4 +10,67 @@
  * SPI SCK     SCK          13 / ICSP-3
  */
 
+#include <SPI.h>
+#include <MFRC522.h>
 
+#define SS_PIN 10
+#define RST_PIN 9
+#define READ_MODE_LED A0
+#define WRITE_MODE_LED A4
+#define READ_MODE_BUTTON 7
+#define WRITE_MODE_BUTTON 6
+
+int mode = 0; //0 read, 1 write
+int buttonStateRead = 0;
+int buttonStateWrite = 0;
+
+MFRC522 rfid(SS_PIN, RST_PIN);
+
+MFRC522::MIFARE_Key key;
+
+void setup() {
+    Serial.begin(9600);
+    SPI.begin();
+    rfid.PCD_Init();
+    pinMode(READ_MODE_LED, OUTPUT);
+    pinMode(WRITE_MODE_LED, OUTPUT);
+    pinMode(READ_MODE_BUTTON, INPUT);
+    pinMode(WRITE_MODE_BUTTON, INPUT);
+    
+    digitalWrite(READ_MODE_LED, HIGH);      
+}
+
+void loop() {
+  
+  
+  if (!rfid.PICC_IsNewCardPresent() || !rfid.PICC_ReadCardSerial()) {
+    return;
+  }
+
+  Serial.print(F("PICC type: "));
+  MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak);
+  Serial.println(rfid.PICC_GetTypeName(piccType));
+
+  // 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) {
+    Serial.println(F("Your tag is not of type MIFARE Classic."));
+    return;
+  }
+
+  String strID = "";
+  for (byte i = 0; i < 4; i++) {
+    strID +=
+    (rfid.uid.uidByte[i] < 0x10 ? "0" : "") +
+    String(rfid.uid.uidByte[i], HEX) +
+    (i!=3 ? ":" : "");
+  }
+  strID.toUpperCase();
+
+  Serial.print("Tap card key: ");
+  Serial.println(strID);
+
+  rfid.PICC_HaltA();
+  rfid.PCD_StopCrypto1();
+}