pyfastnet 1.0.2

A Python library for decoding FastNet protocol data streams.

pyfastnet

Fastnet is the propriatory protocol used by B&G on some older instruments, tested on Hydra/H2000. It might work on other systems. I developed this for personal use and publishing for general interest only.

Purpose

This library can be fed a stream of fastnet data, it will decode and return structured instrument data for further processing

Example input/output

Byte string from Fastnet including "ff010a01f541910000420a00000000e2ff050c01ef4e0a02750222520a1a4f1a4fdf"

The decoded values from the frame look like this:

' Boatspeed (Knots): channel_id: '0x41', format_byte: '0x91', data_bytes: '0000', divisor: 100, digits: 2, format_bits: 1, raw: 0, interpreted: 0.0 '

Important library calls

• 'fastnetframebuffer.add_to_buffer(raw_input_data)'
• 'fastnetframebuffer.get_complete_frames()'
• 'set_log_level(DEBUG)'

Companion App

• Fastnet to NMEA converter

Installation

pip3 install pyfastnet

On a raspberry pi this is done from with a virtual env python -m venv --system-site-packages ~/python_environment source ~/python_environment/bin/activate pip3 install pyfastnet deactivate

~/python_environment/bin/python3 myapp.py

Acknowledgments / References

• trlafleur - Collector of significant background
• Oppedijk - Background
• timmathews - Significant implementation in Cpp
• Significant help from chatGPT!