Termnetd (aka termpkg apparently) is a cool little application that lets you stream serial port data over the network. It’s a terminal server daemon that exposes the serial port and tty devices directly to a network port.

The setup is pretty simple. If using Ubuntu, you can just use:

sudo apt-get install termnetd

Otherwise, you can build from source by downloading it from http://www.linuxlots.com/~termpkg/

Configuration

Once installed, the configuration file, /etc/termnetd.conf, can be edited to configure which serial port maps to which network port. It can be used to set serial port connection settings as well. The format is as follows:

<IP port>:<state>:<device>:<termios options>;

Example:

3000:on:/dev/ttyS0:B115200 CLOCAL IGNBRK CRTSCTS CS8 CREAD;

In Ubuntu, /etc/default/termnetd, there is a NO_START option that can be set to let termnetd start automatically at boot up.

You can also refer to termnetd(1)

Usage

Start termnetd by running

termnetd or /etc/init.d/termnetd start from the command line. From another terminal use telnet or netcat to receive the data

nc localhost 3000

I work with embedded systems and termnetd has been great for me. I am now able to run this on the target and use python or any other flexible interpreted language on the host side.