Hi,
I was facing the same problem as others here in that thread.
For whatever reason the following line was constantly set in ~/.arduino/preferences.txt:
serial.debug_rate=38400
Changing that line to
serial.debug_rate=9600
made that /dev/ttyACM0 appeared just before uploading. But still I received the error:
...processing.app.SerialException: Error opening serial port '/dev/ttyACM0'...
What helped me is change the entry to serial.debug_rate=9600, then I made the file read-only.
I restarted the IDE and the above mentioned line was kept to serial.debug_rate=9600.
Very strange....
Regards
AgeBee
iranon727:
Hi,
I just ran into exactly the same problem. I have no idea what was going on, but deleting ~/.arduino/preferences.txt fixed it for me.