python-aprs / aprs3

Python library for encoding and decoding APRS packets supporting RX/TX via APRS-IS or KISS

aprs3 - Python APRS Module

aprs3 is a module for encoding and decoding APRS data for use with AX.25 or APRS-IS.

Supported Data Types

• Position (PositionReport)
  • Compressed
  • Uncompressed
  • w/ Timestamp
  • Data Extension
    • Course / Speed
    • PHG
    • RNG
    • DFS
  • Altitude
• Object (ObjectReport)
• Item (ItemReport)
• Status (StatusReport)
• Message (Message)

Unknown data types will be decoded as InformationField.

Interfaces

This package supplies async methods for interacting with APRS-IS:

import asyncio
from aprs import create_aprsis_connection

async def main():
    transport, protocol = create_aprsis_connection(
        host="noam.aprs2.net",
        port=14580,
        user="KF7HVM",
        passcode="-1",  # use a real passcode for TX
        command='filter r/46.1/-122.9/500',
    )

    async for frame in protocol.read():
        print(frame)

if __name__ == "__main__":
    asyncio.run(main())

Synchronous wrappers are also included where that may be more convenient:

from pprint import pformat

import attrs

import aprs

with aprs.TCP(
    host="noam.aprs2.net",
    port=14580,
    user="KF7HVM",
    passcode="-1",  # use a real passcode for TX
    command='filter r/46.1/-122.9/500',
) as aprs_tcp:
    # block until 1 frame is available and print repr
    print(repr(aprs_tcp.read(
        callback=lambda f: print(f),
        min_frames=1,
    )[0]))

    # block until 3 frames are available and print decoded form
    for frame in aprs_tcp.read(min_frames=3):
        print(pformat(attrs.asdict(frame)))

Additionally, this package may be used with real TNCs via Serial KISS or KISS-over-TCP.

• serial:
  • sync: aprs_serial = aprs.SerialKISS("/dev/ttyUSB0", 9600)
  • async: transport, protocol = aprs.create_serial_connection("/dev/ttyUSB0", 9600)
• tcp:
  • sync: aprs_kiss_tcp = aprs.TCPKISS("localhost", 8001)
  • async: transport, protocol = aprs.create_tcp_connection("localhost", 8001)

These objects are used in the same way as the sample shown above.

For versions of the KISS transports which do NOT automatically encode/decode APRS data, see kiss3.

Versions

• 8.x.x branch is a large rewrite including async functionality and full packet encoding.

Previous versions were released by ampledata as aprs:

• 7.x.x branch and-on will be Python 3.x ONLY.
• 6.5.x branch will be the last version of this Module that supports Python 2.7.x

Installation

Install from pypi using pip: pip install aprs3

Usage Examples

Example 1: Library Usage - Receive

The following example connects to APRS-IS and filters for APRS frames within 500 miles of 46.1N, 122.9W. Any frames returned are sent to the callback p, which prints them.

Example 1 Code

:

import aprs

def p(x): print(x)

with aprs.TCP(command='filter r/46.1/-122.9/500') as aprs_tcp:
    # callback can be passed to read()
    aprs_tcp.read(callback=p)

Example 1 Output

W2GMD-6>APRX28,TCPIP*,qAC,APRSFI-I1:T#471,7.5,34.7,37.0,1.0,137.0,00000000

Example 2: Library Usage - Send

The following example connects to APRS-IS and sends an APRS frame.

Example 2 Code

import aprs

frame = aprs.APRSFrame.from_str('KF7HVM-2>APRS:>Test from aprs!')

with aprs.TCP(user='W2GMD', passcode='12345') as a:
    a.write(frame)

Testing

Run pytest via tox:

tox

See Also

• Python kiss3 Module Library for interfacing-to and encoding-for various KISS Interfaces.
  • Forked from ampledata/kiss
• Python APRS Gateway Uses Redis PubSub to run a multi-interface APRS Gateway.
• Python APRS Tracker TK.
• dirus Dirus is a daemon for managing a SDR to Dire Wolf interface. Manifests that interface as a KISS TCP port.

Similar Projects

• apex by Jeffrey Phillips Freeman (WI2ARD). Next-Gen APRS Protocol. (based on this Module! :)
• aprslib by Rossen Georgiev. A Python APRS Library with build-in parsers for several Frame types.
• aprx by Matti & Kenneth. A C-based Digi/IGate Software for POSIX platforms.
• dixprs by HA5DI. A Python APRS project with KISS, digipeater, et al., support.
• APRSDroid by GE0RG. A Java/Scala Android APRS App.
• YAAC by KA2DDO. A Java APRS Client.
• Ham-APRS-FAP by aprs.fi: A Perl APRS Parser.
• Dire Wolf by WB2OSZ. A C-Based Soft-TNC for interfacing with sound cards. Can present as a KISS interface!

Source

Github: https://github.com/python-aprs/aprs3

Authors

Greg Albrecht W2GMD [e-mail]

http://ampledata.org/

Masen Furer KF7HVM [e-mail]

Copyright

Copyright 2022 Masen Furer and Contributors

Copyright 2017 Greg Albrecht and Contributors

Automatic Packet Reporting System (APRS) is Copyright Bob Bruninga WB4APR [e-mail]

decimaldegrees.py - Copyright (C) 2006-2013 by Mateusz Łoskot <[e-mail]>

License

Apache License, Version 2.0. See LICENSE for details.

decimaldegrees.py - BSD 3-clause License

base91.py - GPL