title: Tello Can't Land
body: <p>I was trying to control Tello by python, but the drone couldn't land; it always shows the decryption of the message in the drone was wrong. Here's the output:</p>
  <pre><code>[INFO] tello.py - 421 - Send command: 'land'
  [INFO] tello.py - 445 - Response land: 'unknown command: land`P'
  </code></pre>
  <p>The drone has fallen from the air for a time, so is that the problem?</p>