LinuxQuestions.org
Share your knowledge at the LQ Wiki.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware > Linux - Embedded & Single-board computer
User Name
Password
Linux - Embedded & Single-board computer This forum is for the discussion of Linux on both embedded devices and single-board computers (such as the Raspberry Pi, BeagleBoard and PandaBoard). Discussions involving Arduino, plug computers and other micro-controller like devices are also welcome.

Notices



Reply
 
Search this Thread
Old 06-20-2014, 08:30 PM   #1
youpet
LQ Newbie
 
Registered: Jun 2014
Posts: 2

Rep: Reputation: Disabled
ttyUSB0 settings affect stdout on a different uart


I have an atmel926 based SBC with an on-board uart for stdin/stdout/stderr. I've connected a USB device with ftdi USB serial to this SBC. when I open ttyUSB0 and change settings such as baud rate, it affects the uart. Also writing to the ttyUSB0 is output on stdout I.e. the uart channel.

I don't know what is going on. It seems to me that these would be 2 separate serial channels. Is it maybe something in Uboot? Any help would be greatly appreciated!
 
Old 06-30-2014, 07:57 AM   #2
rtmistler
Senior Member
 
Registered: Mar 2011
Location: Milford, MA. USA
Distribution: MINT Debian, Angstrom, SUSE, Ubuntu
Posts: 1,702
Blog Entries: 8

Rep: Reputation: 652Reputation: 652Reputation: 652Reputation: 652Reputation: 652Reputation: 652
Do you know the device identification for the on-board UART? What is it? Because I'm wondering if that is /dev/ttyUSB0 and your added USB serial is /dev/ttyUSB1.

A view of your system log from boot up and then insertion of your serial USB device would be helpful to see if you can post that.

You are correct that they should be 2 separate serial channels.

I don't see why uboot would have any relevance? You are running Linux at the time of these problems, correct?

Other things to check and report:

Code:
cat /proc/tty/driver/usbserial
Code:
dmesg | grep tty >> tty.log
and then post that log; however the entire system log is likely more useful.
 
Old 07-03-2014, 10:07 AM   #3
youpet
LQ Newbie
 
Registered: Jun 2014
Posts: 2

Original Poster
Rep: Reputation: Disabled
Smile solved

dear rtmistler
your comments provided the sanity check I needed. Turns out that I was incorrectly applying settings to the old termios dev. I didn't realize that the samples I found saved the old for restoration purposes and that I needed to create a new termios dev for the new settings.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
tar - write to stdout & create log files ( from stdout and stderr ) [solved] paziulek Linux - General 2 02-23-2014 01:26 PM
Baud rate and other settings settings for Linux UART drivers through ioctls. kauuttt Linux - Kernel 1 10-18-2012 01:50 PM
Where does uart console get its value of uart port membase? unifoxz Linux - Kernel 1 12-20-2011 03:28 PM
Desktop environment color settings: do they affect web browser color? stf92 Linux - Newbie 2 06-14-2011 04:17 PM
redirecting stdout to /dev/null and stderr to stdout? Thinking Programming 1 05-18-2006 03:36 AM


All times are GMT -5. The time now is 06:12 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration