Multi serial port application

[veera]

@mrjj ,
I am directly assigning the portname from gui qcombox is it correct way for accessing the port name ?

[mrjj]

Hi
normally its ttyS4
for
serial->setPortName(p.name);

Did you see the sample
http://doc.qt.io/qt-5/qtserialport-terminal-example.html

Its available directly in Creator and you can use to test.

[veera]

yes i have refer that example only.....

[veera]

i have tried both the things not able to open the port .....

[mrjj]

@veera

so are you sure PC has that port ?

if using a serial usb adapter, it has other name.

If you cannot open port using the Terminal sample then
something is wrong outside Qt.

[veera]

yes having two ports only ttyS4 and ttyS5 i am not using any usb to serial converter i am directly connecting with serial port only .....i have tried terminal example its giving the permission error means sudo permission .....

[veera]

permission is denied error while opening the port in Terminal Sample...

[jsulm]

@veera What does

ls -lh /dev/ttyS4

say?

[mrdebug]

Are you in dialout group?

[veera]

i tried using this command on the qt project path also not able to open the serial ports.....

[veera]

yes i am in dialout group....

[veera]

crw-rw---- 1 root dialout 4, 68 Dec 11 13:22 /dev/ttyS4

[veera]

@jsulm said in multi serial port application:

ls -lh /dev/ttyS4

crw-rw---- 1 root dialout 4, 68 Dec 11 13:22 /dev/ttyS4

[mrdebug]

Are you sure you really have 4 serial ports? Which kind of machine have you got?
In some case, with a beaglebone board for example, you have to enable the third and fourth serial port with a special kernel parameter.

[mrjj]

Hi
Often you have to add your user to the dialout group to be allowed to use it

usermod -a -G dialout MY_USER_NAME

as @mrdebug asks/says

[veera]

@mrdebug
I have only two serial ports i am connecting slot machine to my desktop computer.....need to connect from desktop to slot machine i am struggling to open the serial port please help me i have added like this

[veera]

sudo usermod -a -G dialout veera

[veera]

in my desktop using two serial ports using right now may be in built its four i guess.....

[jsulm]

@veera Make sure your user is member of dialout group

[mrjj]

Also if you are having ONLY 2 serial ports why are you then
trying the /dev/ttyS4 port ???
i would giess on
/dev/ttyS0
or
/dev/ttyS1