can't get second serial port to work (ttyS1)

Discussion in 'Modding Forum' started by hedpe, Jul 5, 2005.

  1. hedpe

    hedpe Network Guru Member

    Hey all,

    I actually have a WAP54G, and followed the WRT54G dual serial port setup.

    I was able to get the first serial port to work, the serial console. I understand the following pinout about the WAP54G:

    O O O O 3.3v, 3.3v, Ground, Ground
    O O O O O ttyS0 output, Unknown, Unknown, ttyS0 input, Unknown

    By following this pinout, my first serial port works. So, therefore I only have 3 unknown pins left... 2 of them have to be a ttyS1 input, and ttyS0 output. So, my first theory was to try every single combination of these pins and I would eventually get a second serial port working. I tried this out, and I couldn't get the second serial port working.

    So then I read that I should just connect ttyS1 input, to ttyS0 output, and pull up my console and do a "cat /dev/tts/1 > /dev/tts/1", and if both input and output are together, I should get an echo back. Well... I tried all combination of wires again with this command, and got no echo.

    So then I kept googling and saw that the WRT54G tries to have both ports share the same IRQ, and this is bad? I really know simple basics about hardware, and I know that two things need seperate IRQs. So my question is, how do I check the IRQ with my serial port console, and how do I change the IRQ so that I can get the second serial port working?

    Or, if anyone has any more suggestions which could help me correctly pinout the last 3 pins so I can find the real ttyS1 in and out :)

    On boot:
    Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ SERIAL_PCI enabled
    ttyS00 at 0xb8000300 (irq = 3) is a 16550A
    ttyS01 at 0xb8000400 (irq = 0) is a 16550A
    From Shell (make sure to expand the code):
    # cat /proc/tty/driver/serial
    serinfo:1.0 driver:5.05c revision:2001-07-08
    0: uart:16550A port:B8000300 irq:3 baud:115740 tx:2190 rx:199 RTS|DTR
    1: uart:16550A port:B8000400 irq:0 tx:0 rx:0 CTS|DSR|CD
  2. Anonymous

    Anonymous Guest

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice