Serial port connection to my board

This is a discussion on Serial port connection to my board within the Embedded forums, part of the Help category; Hi It is the basic thing but something is wrong in my set up. I have a laptop with docking station and I can connect to my development board. Development ...

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  #1  
Old 08-10-2008, 11:15 AM
Default Serial port connection to my board

Hi

It is the basic thing but something is wrong in my set up.

I have a laptop with docking station and I can connect to my
development board. Development board boots and I see
the uboot loader. Hardware of port is NS16550A. Actually it
works even without docking station. Newer laptop year 2003.

I have another laptop without docking station and when
I connect the board there no log in minicom. Hardware
of port is 16550A. Older laptop year 2000.

I use the same cable and same software. Kernels are different but
serial ports are configured when I check dmesg. I set same
values to ports with setserial. One laptop is older than other
but both are IBM ThinkPads.

Is there difference in serial ports (I mean in hardware level)?
Some voltage values are lower than others? I have seen signal
level difference in LPT ports but not in serial ports.

Any suggestions how I can get it work in older laptop?

Thanks
Indrek
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  #2  
Old 08-11-2008, 09:36 AM
Default Re: Serial port connection to my board

nanoip@hotmail.com wrote:

> Hi
>
> It is the basic thing but something is wrong in my set up.
>
> I have a laptop with docking station and I can connect to my
> development board. Development board boots and I see
> the uboot loader. Hardware of port is NS16550A. Actually it
> works even without docking station. Newer laptop year 2003.
>
> I have another laptop without docking station and when
> I connect the board there no log in minicom. Hardware
> of port is 16550A. Older laptop year 2000.
>
> I use the same cable and same software. Kernels are different but
> serial ports are configured when I check dmesg. I set same
> values to ports with setserial. One laptop is older than other
> but both are IBM ThinkPads.
>
> Is there difference in serial ports (I mean in hardware level)?
> Some voltage values are lower than others? I have seen signal
> level difference in LPT ports but not in serial ports.
>
> Any suggestions how I can get it work in older laptop?


Did you also try with handshake signals disabled?

jbe
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  #3  
Old 08-11-2008, 04:29 PM
Default Re: Serial port connection to my board

I know this may sound dumb, but could one laptop's serial port be set
as a DTE while the other is set as DCE ?

If you have a breakout box try swapping pins 2&3 on the serial and see
it that works.

G

On Aug 10, 10:15 am, nan...@hotmail.com wrote:
> Hi
>
> It is the basic thing but something is wrong in my set up.
>
> I have a laptop with docking station and I can connect to my
> development board. Development board boots and I see
> the uboot loader. Hardware of port is NS16550A. Actually it
> works even without docking station. Newer laptop year 2003.
>
> I have another laptop without docking station and when
> I connect the board there no log in minicom. Hardware
> of port is 16550A. Older laptop year 2000.
>
> I use the same cable and same software. Kernels are different but
> serial ports are configured when I check dmesg. I set same
> values to ports with setserial. One laptop is older than other
> but both are IBM ThinkPads.
>
> Is there difference in serial ports (I mean in hardware level)?
> Some voltage values are lower than others? I have seen signal
> level difference in LPT ports but not in serial ports.
>
> Any suggestions how I can get it work in older laptop?
>
> Thanks
> Indrek


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  #4  
Old 08-12-2008, 12:45 PM
Default Re: Serial port connection to my board

Thanks Juergen and gfine

I continued my testings with kermit. There I set handshake off.
Currently I do not have other box for testing.

At least I got something out. I tried to change some values
but no help.

I list here my D9 cable as well

2-3
3-2
4-6
5-5
6-4
7-8
8-7


Thanks, Indrek

--------------------------------------------------------------------
C-Kermit 8.0.211, 10 Apr 2004, for Linux
(/home/nanoip/) C-Kermit>show com

Communications Parameters:
Line: /dev/ttyS0, speed: 115200, mode: local, modem: none
Parity: none, stop-bits: (default) (8N1)
Duplex: full, flow: none, handshake: none
Carrier-watch: off, close-on-disconnect: off
Lockfile: /var/lock/LCK..ttyS0
Terminal bytesize: 8, escape character: 28 (^\)

Carrier Detect (CD): Off
Dataset Ready (DSR): Off
Clear To Send (CTS): Off
Ring Indicator (RI): Off
Data Terminal Ready (DTR): On
Request To Send (RTS): On

(/home/nanoip/) C-Kermit>c

Connecting to /dev/ttyS0, speed 115200
Escape character: Ctrl-\ (ASCII 28, FS): enabled
Type the escape character followed by C to get back,
or followed by ? to see other options.
----------------------------------------------------
óa^ÂN
¥ûÊwŸûYwŸkJ÷ýÇFB'þÒ‚ÂÂBós'P&ï÷þ


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  #5  
Old 08-12-2008, 02:34 PM
Default Re: Serial port connection to my board

And the same newer laptop. Evriting works in kermit like in minicom.

----------------------------------------------------------------------------------------------------
cat .kermrc
set line /dev/ttyS0
set handshake none
set flow-control none
set modem type none
set speed 115200
robust
set carrier-watch off

# kermit
C-Kermit 8.0.211, 10 Apr 2004, for Linux
Copyright (C) 1985, 2004,
Trustees of Columbia University in the City of New York.
Type ? or HELP for help.
(/home/nanoip/) C-Kermit>show comm

Communications Parameters:
Line: /dev/ttyS0, speed: 115200, mode: local, modem: none
Parity: none, stop-bits: (default) (8N1)
Duplex: full, flow: none, handshake: none
Carrier-watch: off, close-on-disconnect: off
Lockfile: /var/lock/LCK..ttyS0
Terminal bytesize: 8, escape character: 28 (^\)

Carrier Detect (CD): Off
Dataset Ready (DSR): Off
Clear To Send (CTS): Off
Ring Indicator (RI): Off
Data Terminal Ready (DTR): On
Request To Send (RTS): On

(/home/nanoip/) C-Kermit>c
Connecting to /dev/ttyS0, speed 115200
Escape character: Ctrl-\ (ASCII 28, FS): enabled
Type the escape character followed by C to get back,
or followed by ? to see other options.

U-Boot 1.1.6 (Jul 18 2007 - 16:32:32)

DRAM: 64 MB
Flash: 64 MB
env_relocate[208] offset = 0x0
env_relocate[226] malloced ENV at a305c008
Hit any key to stop autoboot: 0
## Booting image at 00080000 ...
Bad Magic Number

...... and uboot is there.......

What happens in my older laptop?

Indrek
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  #6  
Old 08-13-2008, 01:47 PM
Default Re: Serial port connection to my board

Hi

I think that my problem is solved!

The laptop is so old that there are problems with ACPI.
I have compiled kernel 2.6.22. In dmesg I noticed
that ACPI is disabled automatically by kernel
but it seems that it is not enough.

I disabled acpi in menu.lst as kernel parameter.

Thanks
Indrek
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