title: Arduino OTA Firmware Backup ESP32
body: <p>It is widely known that you can update firmware over-the-air using <code>&lt;Update.h&gt;</code> functionality: receive blob size over the network, call <code>Update.begin(blob_size)</code>, consecutively call <code>Update.write()</code> until its done, then call <code>Update.end()</code>, and restart the board.</p>
  
  <p>But is there a way to do a backup of current firmware binary using WiFi?</p>