Cannot open Serial Port using CuteCom

[houmingc]

I am using Cutecom to connect to my device
When i "open device", Error "could not open /dev/ttyUSB0

sudo apt-get install cutecom
may i know where is cutecom installed. <Which CuteCom not working>

Finding ports ttyUSB0 connected
dmesg |grep tty shows ttyUSB0 connected
usb 2-1.3:pl203 now attached to ttyUSB0

I have check with lsusb, and device is connected

I set the baud rate, data bits, stops bits and hex input at the right bottom.
I tried with minicom, but i can't open serial port too

[SGaist]

Hi,

Not really a Qt question but anyway, do you have the rights to access your device ?

[houmingc]

sudo chmod a+rw /dev/ttyUSB0

works

[SGaist]

And that's a security hole wide open.

You should rather add your user to the correct group.

[houmingc]

It is troublesome to run this command everytimes.
Is there other alternatives?

[SGaist]

Yes there is. What I suggested in my last message

[houmingc]

I do not know what is the benefit of doing so.
Below is the steps on 'how to add user to correct Group'?
What is the difference between primary and secondary group

@
First, list all group $ cut -d: -f1 /etc/group
Second, login as root user, $ su -
Third, add user: $ sudo adduser new_username
& add group: $ groupadd groupname
& add user into group $ useradd -G groupname new_username
Fouth, grant sudo privilege $visudo
below root, add newuser ALL=(ALL:ALL) ALL
Fifth, save and closed Ctrl + X
@

[SGaist]

The benefit ? You don't allow everybody and anybody the rights to access the serial port.

The secondary groups are just the additional groups your user is part of e.g. dial out

@useradd -G dialout username@
is a bit simpler

[houmingc]

CuteCom can always open serial port but Qt program open serial port sometimes. What is the solution

[SGaist]

Is there a pattern when it fails to open the device ? Did you check if there's an error message returned by QSerialPort ?