Serial Communication in Maltab using Linux 64 Bit

I use Matlab 2015a (64 Bit) on a Ubuntu Linux distribution system. I want to build a communication to a device with a RS232 port. For this task I use a USB to RS232 converter cabel. In Linux I get the information, that the cable is connected to ttyUSB0. But if i want to start the communication over Matlab with:

s = serial('/dev/ttyUSB0', 'BaudRate', 9600);
fopen(s)

I get the error:

Error using serial/fopen (line 72)
Open failed: Port: /dev/ttyUSB0 is not available. ....

I tested this process on a WIN System and there is no problem. The communication runs pretty well. Have anyone experieances with Linux/Matlab and serial communication?

[William Harwin]

This is in fact a Linux permissions problem rather than a Matlab problem. To test permissions see if there is a difference between

 sudo stty -a -F /dev/ttyUSB0

and

 stty -a -F /dev/ttyUSB0

If the latter says 'permission denied' or similar then you are probably not a member of the relevant group. The group on the USB port can be seen by using

 ls -l /dev/ttyUSB0

and can be changed via

 sudo usermod -aG groupname username

e.g.

 sudo -aG dialout harrypotter

Check membership via the `group' command (a reboot may be necessary)

Answer 1

[Álvaro Cortés Sánchez-Migallón]

I followed other way. I got exactly the same error (Over Manjaro distribution) and of course is about permissions:

• From terminal:

sudo chmod +777 /run/lock

sudo chmod +777 /dev/ttyACM0

• From Matlab:

% Scan all serial ports

serialPorts = serialportlist

% Get serial port i want as serial communication

ACM0 = serial(serialPorts(1))

% Open file (now works)

fopen(ACM0)

% Read data all data available

data = fread(ACM0, ACM0.BytesAvailable);

[Ravi Kiran Aggadi]

Thanky you! the solution that you have mentioned helpd me in resolving the problem.

Answer 2

[Dasharath Gulvady]

The below answer may be relevant:

http://www.mathworks.com/matlabcentral/answers/95024-why-is-my-serial-port-not-recognized-with-matlab-on-linux-or-solaris