A Python Serial logger implementation and serial port CLI using observer pattern

The file main.py show cases an application using observer pattern from py-observer package to read from a serial port (real or fake) and provides a CLI for logging to console (always on) and file by offering different options. In addition, the overall design is an example of sustainable design following the SOLID principles popularized by uncle Bob aiming to provide a flexible design easy to maintain.

The serial reader- and file writer threads uses callbacks for communicating with the application if they fail. The program waits for the user to enter any key to quit the program.

Run the serial logger CLI in your terminal for help instructions:

$ python main.py -h
usage: main.py [-h] [-d] [-l LOGFILE] [-f] -p PORT [-t]

Serial Logger CLI

You log from a serial port set by name. The serial stream is logged to console.
Writing the stream to a file is an option.
A fake serial stream is an option too and typically useful for development or
unit testing
with fault-injection.
Hit any key to quit the program.

optional arguments:
  -h, --help            show this help message and exit
  -d, --debug           set debug log level
  -l LOGFILE, --logfile LOGFILE
                        set log to file
  -f, --fake            set fake serial
  -p PORT, --port PORT  set serial port
  -t, --timestamp       add timestamp in logging

  main.py -p COM1
  main.py -p COM1 -f -l serial.txt

For example writing to console and log file from fake serial port at the same time with debug printing:

$ python main.py -p COM1 -f -l serial.txt

List ports

Run the serial port helper CLI in your terminal for help instructions:

$ python serialporthelper.py -h
usage: serialporthelper.py [-h] [-l | -p PORT]

List serial ports CLI

optional arguments:
  -h, --help            show this help message and exit
  -l, --listports       list serial ports
  -p PORT, --port PORT  check if a port is available

  serialporthelper.py -l
  serialporthelper.py -p COM1

Prerequisites

OBS! Works for Python2.6+ only! Install python

Dependencies

Install pySerial

Install py-observer package.

Install these using the requirement.txt file:

$ pip install -r requirements.txt

Limitations

The serial logger CLI program currently only works for serial ports over usb, since it does not provide any port configuration. However, you may always change the call to Serial in main.py to your special needed settings.