title: Bluetooth LE data JSON in 20 bytes
body: <p>I have a Bluetooth LE module on Arduino which sends a JSON string to an Android application.</p>
  
  <p>The JSON string look like this:</p>
  
  <pre><code>{'d_stats':[{'t':'26.62','h':'59.64','p':'755.23','a':'109.02','hrm':'0.00'}]}
  </code></pre>
  
  <p>The Android app receives packets of 20 bytes (20 characters limit) and I can't find a method to put all packets together when the last packet was received.</p>
  
  <p>Is there a way to know when the last packet is received?</p>
  
  <p>Edit: the bluetooth sends data at a constant interval of time. There is a button connected to the Arduino board which, when pushed, will send other data via Bluetooth. The problem is that it overlaps with the timed transmission.</p>