[SOLVED] Serial port

[bkv1958]

Hi

I need to use the serial port on my Dell Latitude D630, but the application can't find it. Neither can I find it in the hardware section of Mageia Control Center. do you know what the problem is?

Thanks.

[doktor5000]

Maybe you want to have a look at http://www.cyberciti.biz/faq/find-out-l ... setserial/ ?

[bkv1958]

Maybe you want to have a look at http://www.cyberciti.biz/faq/find-out-l ... setserial/ ?

Thanks,
I get this out

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/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4


Still, my application says there is no serial port.

[Ken-Bergen]

Still, my application says there is no serial port.

Perhaps telling us what the application is would help, or is that top secret?

[bkv1958]

Still, my application says there is no serial port.

Perhaps telling us what the application is would help, or is that top secret?

No it is not secret It is JMRI, a java application. http://jmri.sourceforge.net/

I had also expected to see the serial port in the hardware section of the control center.

[djennings]

Take a look at the permissions of /dev/ttyS0 Maybe your user does not have permission to access it.

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ls -l /dev/ttyS0

[bkv1958]

I get this:
crw-rw---- 1 root dialout 4, 64 Apr 29 11:00 /dev/ttyS0

[djennings]

I get this:
crw-rw---- 1 root dialout 4, 64 Apr 29 11:00 /dev/ttyS0

There is your problem. The port is owned by root and members of the group dialout can access it, but others cannot.
The solution is to open MageiaControlCentre>System>Users>Groups and edit the group dialout to add yourself as a member.

[bkv1958]

still no luck. Is there an other program which I could try, that would look for serial ports?

[djennings]

Tp test a serial port
http://www.cyberciti.biz/faq/find-out-linux-serial-ports-with-setserial/
setserial is in the setserial package. You may need to install it

To confirm you are a member of the dialout group

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more /etc/groups | grep dialout

[bkv1958]

This is what I get

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[bjorn@localhost rsync]$ setserial -a /dev/ttyS0
/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test


more /etc/group | grep dialout
dialout:x:83:bjorn



[juergen_harms]

In case your problem is not yet sorted out:

- If you launch your application by clicking a menu or desktop item, you should look what happens if you launch it from a command line in a shell console - the application might print valuable information to its standard or error output that might contain helpful information

- Many tty applications use the /var/lock/tty directory for creating lock files that prevent several applications using the tty port in an uncoordinated way. Mageia does not create that directory by default (and I do not know whether your applications really needs it - is there documentation, for instance in a README file?). Nevertheless, may be worth while to try to create one if problems persist; you do that from a shell console and with root privileges:

mkdir /var/lock/tty
chgrp dialout /var/lock/tty
chmod g+w /var/lock/tty

will create such a directory (and does not do any harm). Sorry for this "preventive dump" - I dont regularly visit this forum

[djennings]

This is what I get

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[bjorn@localhost rsync]$ setserial -a /dev/ttyS0
/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test


more /etc/group | grep dialout
dialout:x:83:bjorn



That looks like it is working to me.
To confirm operation you can use minicom to output characters to the port and receive responses assuming you know how to control whatever is on the other end. There is a minicom package in Mageia.
http://en.wikipedia.org/wiki/Minicom

[bkv1958]

Thanks, I got it to work. Must say, I am no quite certain what did the trick. At least I learned something abount dealing with serial ports, thanks