title: BLE : How can i create my own base UUID and alias
body: <p>I know i can create my own service with BLE by using a 128 bit UUID using a too like <em>uuidgen</em> on Mac.
  But i'm really confused with the way to define an alias and a base UUID for my service.
  Indeed, a base UUID need to get the form of:</p>
  
  <pre><code>0x0000xxxx-1213-XYZA-1523-781FEABCD123 
  </code></pre>
  
  <p>and the alias </p>
  
  <pre><code>Service 0x1523 : 0x00001523-1213-XYZA-1523-781FEABCD123
  characteristic 0x1524 : 0x00001524-1213-XYZA-1523-781FEABCD123
  </code></pre>
  
  <p>But when i generate a uuid i get something like:</p>
  
  <pre><code>580663F1-AFF1-457F-9F79-0F2BF3E11892
  </code></pre>
  
  <p>How can i specify the alias in order to identify the Service and the characteristics ? Do i need to remove the first part ?
  Or am i completly wrong and do i need to do something else to get them ?</p>
  
  <p>How do i managed to generate a base UUID like the Bluetooth SIG one ?</p>
  
  <p>Thanks</p>