GPSD for GeoClue2 using NMEA over TCP

README.md

CLUE-NMEA-GPSD

GPSD for GeoClue2 using NMEA over TCP.

Installation

1. Copy the XML file to /etc/avahi/services/nmea-0183.service.
2. Run glue.py in order to start the service (listens on 10110/tcp).
3. Optionally create a service (systemd or the like) for it to start at boot.
4. Optionally disable all GeoClue2 sources except network-nmea to use GPS only.

Notes

• Make sure you have GPSD enabled (sudo systemctl enable --now gpsd.socket).
• Make sure you have a hardware GPS connected and configured in GPSD.
• This version doesn't handle reconnections to GPSD yet.

glue.py

#!/usr/bin/env python3

from socket import socket, AF_INET, SOCK_STREAM, IPPROTO_TCP, TCP_NODELAY
from socketserver import TCPServer, ThreadingMixIn, StreamRequestHandler


class ServerHandler(StreamRequestHandler):
    def handle(self):
        print("connected %s:%d" % self.client_address)
        gpsd = socket(AF_INET, SOCK_STREAM)
        gpsd.setsockopt(IPPROTO_TCP, TCP_NODELAY, True)
        gpsd.connect(("127.0.0.1", 2947))
        with gpsd.makefile("brw", 0) as upstream:
            upstream.readline()  # consume VERSION report
            upstream.write("?WATCH={\"enable\":true,\"nmea\":true}".encode())
            upstream.readline()  # consume DEVICES report
            upstream.readline()  # consume WATCH report
            while True:
                try:
                    self.wfile.write(upstream.readline())
                except BrokenPipeError:
                    break
        gpsd.close()
        print("disconnected %s:%d" % self.client_address)


class ThreadedTCPServer(ThreadingMixIn, TCPServer):
    pass


def main():
    try:
        with ThreadedTCPServer(("0.0.0.0", 10110), ServerHandler) as server:
            server.serve_forever()
    except KeyboardInterrupt:
        print()


if __name__ == "__main__":
    main()

nmea-0183.service.xml

<?xml version="1.0" standalone="no"?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
	<name replace-wildcards="yes">%h</name>
	<service>
		<type>_nmea-0183._tcp</type>
		<port>10110</port>
		<txt-record>accuracy=exact</txt-record>
	</service>
</service-group>