Greetings Monks,

I have some code that I have been running for months with no problems. The code opens a serial port, collects messages at 9600 baud and displays the proprietary format data in a collection of Perl Tk windows. Once again, this has been running great.

I now need to leave the box in my office and set up another in a lab. I have several Ubuntu 7.04 and 7.10 boxes available so I assumed there would be no problem. But, I am not able to open the serial port on either of the two boxes I have tried so far. Here are some of the details:

Key code lines from big file that has AND STILL DOES work ok on one box:
      use Device::SerialPort
      my $serial_port = new Device::SerialPort("/dev/ttyS0") || die "can't open ttyS0\n";

I have done both an "apt-get install libdevice-serialport-perl" and built the SerialPort module using the EXACT SAME downloaded file and instructions that were used on the working box.

Downloaded file: Device-SerialPort-1.002001.tar.gz downloaded on 06-29-2007.

Build instructions from http://www.sendpage.org/device-serialport/README.txt. This was downloaded and archived on 06-29-2007.

The downloaded instructions were:
      untar
      perl Makefile.PL
      make
      make test
      make install

My error message is: "can't getattr: Input/output error at ./(my_file_name.pl) line (line_with_new_Device::SerialPort).

After Googling I have tried:
      chmod a+rwx /dev/ttyS0
      chown me:me /dev/ttyS0
      execution from user "me" and user "root" tried.

After Googling I don't seem to be getting much that looks useful (and I understand) beyond changing permissions. Any suggestions would be appreciated.

Also, if a "fix" won't hold past a power cycle then I would like to add a part 2 "how to I make a fix that will survive a power cycle?".

And one more: I think it is GREAT that Linux has "ls", "lspci" and "lsusb". With these great features I was suprised that there does not seem to be a "lstty". Since my problem might be my Linux configuration and not Perl, what tools are available to me to gain information on my configuration? CuteCom seems happy wiht ttyS0 so I am using that to make the assumption that my hardware is ok.

Thanks,
Bruce

In reply to can't open ttyS0 with Device::SerialPort by Bruce32903

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