initial commit

examples/ntag21x_rw/ntag21x_rw.ino

@@ -0,0 +1,72 @@
+
+// Clean resets a tag back to factory-like state
+// For Mifare Classic, tag is zero'd and reformatted as Mifare Classic
+// For Mifare Ultralight, tags is zero'd and left empty
+
+
+#if 0       // Using PN532's SPI (Seeed NFC shield)
+#include <SPI.h>
+#include <PN532_SPI.h>
+#include <PN532.h>
+#include <NfcAdapter.h>
+
+PN532_SPI intf(SPI, 10);
+PN532 nfc = PN532(intf);
+#else        // Using PN532's I2C
+#include <Wire.h>
+#include <PN532_I2C.h>
+#include <PN532.h>
+#include <NfcAdapter.h>
+
+PN532_I2C intf(Wire);
+PN532 nfc = PN532(intf);
+#endif
+
+// Using PN532's UART (Grove NFC)
+
+// #include <PN532_I2C.h>
+// #include <PN532.h>
+// #include <NfcAdapter.h>
+// PN532_HSU intf(Serial1);
+// PN532 nfc = PN532(intf);
+
+
+uint8_t password[4] =  {0x12, 0x34, 0x56, 0x78};
+uint8_t buf[4];
+uint8_t uid[7]; 
+uint8_t uidLength;
+
+void setup(void) {
+    Serial.begin(9600);
+    Serial.println("NTAG21x R/W");
+
+    nfc.begin();
+    nfc.SAMConfig();
+}
+
+void loop(void) {
+    Serial.println("wait for a tag");
+    // wait until a tag is present
+    while (!nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength)) {
+
+    }
+
+    // if NTAG21x enables r/w protection, uncomment the following line 
+    // nfc.ntag21x_auth(password);
+
+    nfc.mifareultralight_ReadPage(3, buf);
+    int capacity = buf[2] * 8;
+    Serial.print(F("Tag capacity "));
+    Serial.print(capacity);
+    Serial.println(F(" bytes"));
+
+    for (int i=4; i<capacity/4; i++) {
+        nfc.mifareultralight_ReadPage(i, buf);
+        nfc.PrintHexChar(buf, 4);
+    }
+
+    // wait until the tag is removed
+    while (nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength)) {
+
+    }
+}