Changes
{"action": "insert","id":7,"text": "server4.domain.ch","position_x":1,"position_y": 24,"position_lenght": 78,"scroll_speed": 5,"scroll_index":0,"red": 0,"green": 0,"blue": 3}
{"action": "insert","id":8,"text": "WARNING","position_x": 86,"position_y": 24,"position_lenght": 46,"scroll_speed": 0,"scroll_index":0,"red": 1,"green": 1,"blue": 1}
</pre>
<pre>
To delete default text (as root):
echo "{\"action\": \"delete\",\"id\":0}" > /dev/ttyACM0
</pre>