Serial help - minicom?

[Bill Moseley <moseley@hank.org>]

I've got an Access Point that has a serial port.  The AP runs Linux
(it's an Netgear WG302).  I can't connect to it from Linux using
minicom.

After messing with it for an hour I brought out an old Win95 machine
with hyperterm and was able to connect no problem.  So, AP and cable 
are working fine.

I suspect it's minicom that's causing me problems.  Likely flow
control.  Minicom always reports "OFFLINE".

Anyway, I have two serial ports.  I think they both are operational --
hardware wise.

I do have a device on ttyS0 that works fine.  (It's an
X10 remote control).  So I know that serial port works.

I've tried:

- using both serial ports to talk with the AP, since I know ttyS0
  works with my other device.

- used a null-modem connector to try and talk with the Windows
  hyperterm.  No luck.  I made sure all settings matched on both
  machines.  I even tried echo "hello" > /dev/ttyS1

- I use setserial to set the baud rate to what the AP wants 9600 N 8 1

    bumby:/home/moseley# setserial -ag /dev/ttyS*
    /dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
            Baud_base: 115200, close_delay: 5000, divisor: 0
            closing_wait: 37856
            Flags: spd_normal skip_test

    /dev/ttyS1, Line 1, UART: 16550A, Port: 0x02f8, IRQ: 3
            Baud_base: 9600, close_delay: 50000, divisor: 0
            closing_wait: 50880
            Flags: spd_normal skip_test

- I've looked at /proc/tty/driver/serial and can see "CTS" change when
  I remove the cable from the AP:

    bumby:/home/moseley# cat /proc/tty/driver/serial | grep ^1
    1: uart:16550A port:000002F8 irq:3 tx:0 rx:0 CTS

    <remove cable from Access Point>

    bumby:/home/moseley# cat /proc/tty/driver/serial | grep ^1
    1: uart:16550A port:000002F8 irq:3 tx:0 rx:0


- I'm not using flow control:

    bumby:/etc/minicom# cat minirc.dfl 
    # Machine-generated file - use "minicom -s" to change parameters.
    pu port             /dev/ttyS1
    pu baudrate         9600
    pu mdropdtr         0
    pu updir            /tmp
    pu downdir          /tmp
    pu scriptdir        /tmp
    pu hasdcd           No 

- Just for "fun" I tried changing hasdcd to Yes and mdropdtr to 1 with
  out any change.


- I know minicom is sending chars.  Notice the tx:0 count above in the
  output of /proc/tty/driver/serial 

    bumby:/etc/minicom# cat /proc/tty/driver/serial | grep ^1
    1: uart:16550A port:000002F8 irq:3 tx:0 rx:0 CTS

    <start minicom -- it sends modem init string (how to disable?)

    bumby:/etc/minicom# cat /proc/tty/driver/serial | grep ^1
    1: uart:16550A port:000002F8 irq:3 tx:34 rx:5 brk:5 RTS|CTS|DTR

    <minicom still says "OFFLINE">

Hitting keys in the minicom window will bump up the tx: count.

- Moving the cable from my linux box to Windows Hyperterm works right
  away -- I see the prompt from the AP

What am I doing wrong?


-- 
Bill Moseley
moseley@hank.org