Reading data from a serial port Post: 302919881

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Operating Systems Linux Debian Reading data from a serial port Post 302919881 by wisecracker on Sunday 5th of October 2014 09:26:20 AM

10-05-2014

Registered User

Sometimes a serial transfer can be a RPITA...
There is usually a buffer of _at_least_ 256 bytes to fill first, so........
........try this sequence of events as a starter test mode from root TO assume a 3 wire system only:-
(RTS and CTS should be ignored using the below.)

Code:

1) Close down your terminal completely and do a reboot of your machine.
2) In root mode open up a new terminal then...
3) Number 4) below is optional...
4) chmod 666 /dev/ttyS0
5) Check the status of your /dev/ttyS0
6) Note that your stty might need -f instead of -F and may already be at 9600bps...
7) stty -F /dev/ttyS0
8) Set up the on board serial I/O to 9600bps and RAW data transfer, in my case, for PCLinuxOS and Debian.
9) Again note that your stty might need -f instead of -F ...
10) stty -F /dev/ttyS0 9600
11) stty -F /dev/ttyS0 raw
12) Finally, again check the status of your /dev/ttyS0
13) And again, note that your stty might need -f instead of -F ...
14) stty -F /dev/ttyS0
15) Now start printing, (blocks of?), characters to the terminal window...
16) cat < /dev/ttyS0
17) It might take a second or so to fill your default serial buffer and may display a 256 byte  burst on each access so be aware.

Hope this works for you...

wisecracker

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LEARN ABOUT DEBIAN

sredird

sredird(8)							      sredird								sredird(8)

NAME

       sredird - RFC 2217 serial port server

SYNOPSIS

       sredird [-i] log-level serial-device lock-file [poll-interval]

DESCRIPTION

       This manual page documents briefly the sredird, program.

       This  program  when  run  through inetd will use the RFC 2217 extensions to TELNET to implement serial commands over the TCP connection and
       interface to a specified serial port.

OPTIONS

       An optional first parameter is '-i' to enable compatability with Cisco IOS.

       The first mandatory parameter is the log level for use in syslog.  The next mandatory parameter is the device node for the  serial  device,
       it  must  be  a	fully  qualified  path.   The  final mandatory parameter is the file name for the lock file to be used to prevent multiple
       instances of sredird from talking to the serial port at the same time, or to allow sharing a port between modem and sredird.

EXAMPLE

       Here is a configuration line for running it from inetd: sredir	       stream  tcp     nowait  root    /usr/sbin/tcpd /usr/sbin/sredird  5
       /dev/modem /var/lock/LCK..modem

AUTHOR

       This  man page was written by Russell Coker <russell@coker.com.au>.  May be freely used and distributed without restriction under the terms
       of the GPL.

       The sredird program was written by Denis Sbragion <d.sbragion@infotecna.it> and Jeffrey Altman <jaltman@columbia.edu>.

Russell Coker <;russell@coker.com.au>				       2.2.0								sredird(8)