The Linux ttyACM0 drama - more details after a lot of experimenting

Hello to everybody,
and thanks for all the tips and explanation. I tried anything you mentioned but unfortunately without success.

Here the software I'm using:

MATLAB Version: 9.1.0.441655 (R2016b)
Operating System: Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u1 (2016-09-03) x86_64
Java Version: Java 1.7.0_60-b19 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
MATLAB Version 9.1 (R2016b)
Simulink Version 8.8 (R2016b)
Control System Toolbox Version 10.1 (R2016b)

What I try out so far:

  • add add the tty and dialout to the user
  • chmod 777 /dev/ttyACM0
  • removed the modemanager

The arduino IDE works pretty well but if I try to connect my arduino uno with Matlab I still received the following error message:

Failed to open serial port /dev/ttyACM0 to communicate with board Uno.
Make sure there is no other MATLAB arduino object for this board. For troubleshooting, see Arduino Hardware Troubleshooting.

I didn't know what happened and I would be appreciate if you can support me with some additional ideas.

Thanks in advance
Matthias