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Old 10th January 2015
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darktrym darktrym is offline
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Default capture serial communication with socat

Hello,
i tried to record the complete communication between my laptop and a serial device. NetBSD identies this as uslsa. I can connect via pyserial on ttyU0. Now i want to save the complete communication in both directions. So i use socat to create a pseudo device which connects to the real hardware over the tunnel. I use the following[1] command but nothing happens. Neither on the screen nor in log file.

[1]
Quote:
socat -d -lf /tmp/log.txt -v -x PTY,link=/tmp/serial,wait-slave,raw /dev/ttyU0,raw
Any ideas what igoes wrong?
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Old 10th January 2015
J65nko J65nko is offline
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You can capture serial communication to file with tip(1) by using the following .tiprc file in your home directory:
Code:
!beautify
record='LOGS/serial-log.txt'
script
verbose
!hardwareflow
This will log everything to ~/LOGS/serial.txt
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Old 10th January 2015
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darktrym darktrym is offline
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I don't see how this could solve the problem. The connection is between a laptop and a micocontroller based device, a simple raw uart connection. When i started cu os the create a empty log file. Why should cu record data when it is not man in the middle?
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Old 10th January 2015
J65nko J65nko is offline
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Apparently I either did not understand the problem and/or you did not describe it fully

Anyway, tip will capture serial data that arrives or comes in at the serial port it is connected to. It does log this data but does this buffered. That means only when it has saved up a rather large chunk of data it will be written to the log file. Sometimes the log file will only be written when exiting tip.

BTW this buffering mechanism could be the reason why you do not see any data in the socat log file (yet).

If you have a non-interactive program on your laptop that uses an USB to serial port to communicate (send and receive) then indeed you need something that acts as a man-in-the-middle.
Or you need to extend that program to log everything to file.

Two weeks ago I started writing a Perl script as a tip replacement. It forks a child process:
  • The parent process reads the serial device and copies it to stdout
  • The child process reads stdin and writes it to serial device

It still has a lot of imperfections but I am willing to share/post it here.
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