PyVirtualSerialPorts

A Python implementation of virtual serial ports. Useful for developing and testing programs which need to talk to a serial port.

You can:

• Create a virtual port which echoes back any data sent to it:

• Create a two or more ports; sending data to one sends data to the others:

• Monitor what is being sent between the ports:

It should work on Python 3.5+, however is only tested on supported Python versions.

Has no dependencies other than the Python standard library.

Currently works on *nix type systems. Tested on Ubuntu and MacOS, but should work on others e.g. BSD. Windows support is being worked on.

Installation

Install for current user

$ pip3 install PyVirtualSerialPorts

Install system-wide

$ sudo pip3 install PyVirtualSerialPorts

Running

If the script install folder is in your PATH (almost certainly the case if installed as root), you can simply run:

$ virtualserialports ...

Otherwise, you can use it as a module:

$ python3 -m virtualserialports ...

Usage

usage: virtualserialports [-h] [-l] [-d] num_ports

positional arguments:
  num_ports       number of ports to create

optional arguments:
  -h, --help      show this help message and exit
  -l, --loopback  echo data back to the sending device too
  -d, --debug     log received data to stderr

Examples

Create a single port, and echo back anything sent to it

$ virtualserialports -l 1

The created port will be printed on the command line e.g. /dev/pts/0, and can be used with any serial program, e.g. minicom:

$ minicom -D /dev/pts/0

Create a pair of ports, sending the data between them

$ virtualserialports 2

The two created ports will be printed, and again can be used with any serial program. E.g. in one terminal window:

$ minicom -D /dev/pts/0

and in a second:

$ minicom -D /dev/pts/1

Now typing data on one terminal will appear in the other.

Create three ports, sending data received from any of them to all three

$ virtualserialports -l 3

Use as a library

As of version 2.0.0, much improved support has been added for use as a library, with processing done in the background.

It is recommended to use as a context manager, which will handle setup and clean up nicely:

with VirtualSerialPorts(2) as ports:
    print(f'Port 1: {ports[0]}')
    print(f'Port 2: {ports[1]}')

    # Open and use ports as required.
    # When the context manager ends, ports will be removed.

ports is a list of strings, which can be used to open the ports, e.g with PySerial. A complete example is in example.py.

It can also be used without a context manager as follows:

vsp = VirtualSerialPorts(2)
vsp.open()
# `vsp.ports` is a list of strings of the created ports.

vsp.start()
# Use ports as you wish here.
vsp.stop()
vsp.close()