Question

我正在尝试使用nfc安卓库读取ISO15693 RFID标签：

以下是有关标记的更多信息：http://img42.com/gw07d+

正确读取标签ID，但标签中的数据不是。

onCreate方法：

// initialize NFC
    nfcAdapter = NfcAdapter.getDefaultAdapter(this);
    nfcPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,   this.getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);

onNewIntent方法：

if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction()) || NfcAdapter.ACTION_TECH_DISCOVERED.equals(intent.getAction())) {

        currentTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
        byte[] id = currentTag.getId();
        Tag_data_TextDisplay.setText("TagId:" + Common.getHexString(id));

        for (String tech : currentTag.getTechList()) {

            if (tech.equals(NfcV.class.getName())) {
                NfcV nfcvTag = NfcV.get(currentTag);

                try {
                    nfcvTag.connect();
                    txtType.setText("Hello NFC!");
                } catch (IOException e) {
                    Toast.makeText(getApplicationContext(), "Could not open a connection!", Toast.LENGTH_SHORT).show();
                    return;
                }

                try {
                    byte[] cmd = new byte[]{
                            (byte) 0x00, // Flags
                            (byte) 0x23, // Command: Read multiple blocks
                            (byte) 0x00, // First block (offset)
                            (byte) 0x04  // Number of blocks
                    };
                    byte[] userdata = nfcvTag.transceive(cmd);

                    userdata = Arrays.copyOfRange(userdata, 0, 32);
                    txtWrite.setText("DATA:" + Common.getHexString(userdata));

                } catch (IOException e) {
                    Toast.makeText(getApplicationContext(), "An error occurred while reading!", Toast.LENGTH_SHORT).show();
                    return;
                }
            }
        }
    }

收发方法完成后，

userdata包含一个值为0x02（{ 0x02 }）的字节。

Answer 1

因此，您从{ 0x02 }方法收到transceive的值。如this thread中所示，当您使用未解决的命令时可能会发生这种情况。因此，您应始终通过NfcV发送已解决的命令（因为这似乎支持Android设备上的所有NFC芯片组）。在您的情况下，您可以使用类似的东西生成一个寻址的READ MULTIPLE BLOCKS命令：

int offset = 0;  // offset of first block to read
int blocks = 1;  // number of blocks to read
byte[] cmd = new byte[]{
        (byte)0x60,                  // flags: addressed (= UID field present)
        (byte)0x23,                  // command: READ MULTIPLE BLOCKS
        (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x00,  // placeholder for tag UID
        (byte)(offset & 0x0ff),      // first block number
        (byte)((blocks - 1) & 0x0ff) // number of blocks (-1 as 0x00 means one block)
};
System.arraycopy(id, 0, cmd, 2, 8);
byte[] response = nfcvTag.transceive(cmd);

Android NFC读取ISO15693 RFID标签

1 个答案: