RE: Using Minicom with /dev/ttyU0

["Charles L. Nelson" <charles%embsyspro.com@localhost>]

Hi,
Thanks for your effort, but that did not work either.  I have the same
issues with only one direction of transmission and the computer locking up.
Funny thing is that communicating with my software dev boards work perfectly
fine when I use HyperTerminal under Windows.  But using NetBSD is mandatory
on an upcoming project and I would rather not use a mixture of dev
apparatus.

Maybe I'll try a commercial product next.

Thanks,

CLN

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-----Original Message-----
From: Lubomir Sedlacik [mailto:salo%Xtrmntr.org@localhost] 
Sent: Saturday, April 26, 2008 4:35 PM
To: Charles L. Nelson
Cc: netbsd-users%netbsd.org@localhost
Subject: Re: Using Minicom with /dev/ttyU0

Hello Charles,

On Sat, Apr 26, 2008 at 04:01:39PM -0700, Charles L. Nelson wrote:
> Hi, I've read that Minicom can be used just like HyperTerminal 
> communicate with an embedded system using a null modem cable.  But I 
> have not been able to get it to work.  I can receive data from the 
> embedded system but I can't seem to send any data.
> 
> The Minicom status line shows that Minicom is offline and nothing that 
> I do changes that condition.  Even when it is receiving data is still 
> say's that it is offline.  And when I exit from Minicom after 
> attempting to connect with the embedded system my NetBSD computer 
> locks up and requires a reset.
> 
> I'm running NetBSD 4.0/AMD64 and the version of Minicom that I am 
> using is the current version from the amd64 pkg directory.  Also the 
> USB comm Device is a Belkin F5U049 USB to Serial port.

from tty(4):

 The /dev/ttyXX special file is used for dial-in modems and terminals.
 When a user logs into the system on one of these hardware terminal ports,
the system has already opened the associated device and prepared the line
for normal interactive use (see getty(8)).

 The /dev/dtyXX special file is a SunOS-compatible dial-out device.
 Unlike the dial-in device, opening the dial-out device never blocks.  If
the corresponding dial-in device is already opened (not blocked in the  open
waiting for carrier), then the dial-out open will fail immediately;
otherwise it will succeed immediately.  While the dial-out device is  open,
the dial-in device may not be opened.  If the dial-in open is  blocking, it
will wait until the dial-out device is closed (and carrier  is detected);
otherwise it will fail immediately.

You want to use /dev/dtyU0, not /dev/ttyU0.

Also, you can use cu(1) which is bundled with NetBSD base system, no need
for Minicom in most cases, e.g.:

 # cu -l /dev/dtyU0 -s 9600


regards,

-- 
-- Lubomir Sedlacik <salo@{NetBSD,Xtrmntr,silcnet}.org>   --