title: echo command to serial port in Linux
body: <p>I want to echo something from my Ubuntu host to some device.</p>
  
  <p>It works well if I use putty or minicom.</p>
  
  <p>However, it doesn't work if I do echo from the shell terminal:</p>
  
  <pre><code>echo "cmd" &gt; /dev/ttyUSB0
  </code></pre>
  
  <p>From my device, I saw that the first letter of the cmd is received correctly while the second one received is ASCII bigger than 200. I also have tried to use the "stty" command to adjust the serial communication settings but didn't help. Does anythone know why?</p>
  
  <p>Thanks,</p>