Serial port connection to my board - Embedded

This is a discussion on Serial port connection to my board - Embedded ; 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 ...

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Thread: Serial port connection to my board

  1. 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

  2. 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

  3. 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



  4. 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.
    ----------------------------------------------------
    a^N
    wYwkJFB'҂Bs'P&



  5. 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

  6. 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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