title: Node.js convert hexadecimal number to byteArray
body: <p>I want to send a raw buffer using bluetooth connection. The content is a hex number. Currently I split the number manually to an byte array. Is there any function that can help me convert the number to byte array?</p>
  
  <pre><code>//var data = 0x250001000192CD0000002F6D6E742F72;
  var data = new Buffer([0x25,0x00,0x01,0x00,0x01,0x92,0xCD,0x00,0x00,0x00,0x2F,0x6D,0x6E,0x74,0x2F,0x72]);
  serialPort.write(data);
  </code></pre>