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