isabella232 / chrome-nfc

Chrome App NFC Library

Chrome App NFC Library

With this simple library, you can build a Chrome App that communicates over USB with NFC Readers.

Supported NFC Readers

ACR122U	SCL3711

Play with the Chrome App sample

• Check Developer Mode in chrome://extensions
• Click "Load unpacked extension..." in chrome://extensions and select the sample folder.
• Launch it.

Caveats

Learn more about USB Devices Caveats at https://developer.chrome.com/apps/app_usb#caveats

Usage

Once you've imported the chrome-nfc.js javascript library into your Chrome App, you need to add the permissions below to your manifest file:

"permissions": [
  "usb",
  {
    "usbDevices": [
      { "vendorId": 1254, "productId": 21905 }, // SCL3711
      { "vendorId": 1839, "productId": 8704 }   // ACR122U
    ]
  }
]

Enumerate NFC readers

chrome.nfc.findDevices(function(devices) {
  console.log("Found " + devices.length + " NFC device(s)");
  for (var i = 0; i < devices.length; i++) {
    var device = devices[i];
    console.log(device.vendorId, device.productId);
  }
});

Read NFC tag

chrome.nfc.findDevices(function(devices) {
  var device = devices[0];
  chrome.nfc.read(device, {}, function(type, ndef) {
    console.log(ndef);
    var uri = ndef.ndef[0]["uri"];
    console.log(uri);
    var text = ndef.ndef[1]["text"];
    console.log(text);
  });
});

Write NFC tag

chrome.nfc.findDevices(function(devices) {
  var device = devices[0];
  var ndef = [
    {"text": "Chromium.org website" },
    {"uri": "http://chromium.org" },
    {"aar": "com.google.samples.apps.iosched" },
  ];
  chrome.nfc.write(device, {"ndef": ndef}, function(rc) {
    if (!rc) {
      console.log("WRITE() success!");
    } else {
      console.log("WRITE() FAILED, rc = " + rc);
    }
  });
});

Emulate NFC tag

chrome.nfc.findDevices(function(devices) {
  var device = devices[0];
  var ndef = [
    {"type": "URI", "uri": "http://chromium.org"}
  ];
  chrome.nfc.emulate_tag(device, {"ndef": ndef}, function(rc) {
    if (!rc) {
      console.log("EMULATE() success!");
    } else {
      console.log("EMULATE() FAILED, rc = " + rc);
    }
  });
});

Read Mifare Classic tag (Logic Mode)

chrome.nfc.findDevices(function(devices) {
  var device = devices[0];
  chrome.nfc.read_logic(device, 0, 2, function(rc, data) {
    console.log(UTIL_BytesToHex(data));
  });
});

Write Mifare Classic tag (Logic Mode)

chrome.nfc.findDevices(function(devices) {
  var device = devices[0];
  var data = new Uint8Array([ // NDEF(http://google.com)
    0xdb, 0x00, 0x03, 0xe1, 0x00, 0x00, 0x00, 0x00, // block 0 (MAD1)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // block 1 (MAD1)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x03, 0x0f, 0xd1, 0x01, 0x0b, 0x55, 0x03, 0x67, // block 2 (NDEF)
    0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x63, 0x6f,
    0x6d, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // block 3 (NDEF)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  ]);
  chrome.nfc.write_logic(device, 0, data, function(rc) {
    console.log("WRITE_LOGIC() SUCCESS");
  });
});

Compiling the library

Compiling script requires Python 3.0 and will use online Closure Compiler. Just run

python3 compile.py

and the library will be written to chrome-nfc.js.