gpsd_proto  

The gpsd_proto module contains types and functions to connect to gpsd to get GPS coordinates and satellite information.

gpsd_proto uses a plain TCP socket to connect to gpsd, reads and writes JSON messages. The main motivation to create this crate was independence from C libraries, like libgps (provided by gpsd) to ease cross compiling.

A example demo application is provided in the example sub directory. Check the repository for up to date sample code.

Testing

gpsd_proto has been tested against gpsd version 3.17 on macOS and Linux with these devices:

• Adafruit Ultimate GPS Breakout - PA1616S
• Quectel EC25 Mini PCIe 4G/LTE Module
• u-blox MAX-M8Q
• GPS mice (Adopt SkyTraQ Venus 8)
• iOS app GPS2IP.

Feel free to report any other supported GPS by opening a GitHub issue.

Reference documentation

Important reference documentation of gpsd are the JSON protocol and the client HOWTO.

Development notes

Start gpsd with a real GPS device:

/usr/local/sbin/gpsd -N -D4 /dev/tty.SLAB_USBtoUART

Or start gpsd with a TCP stream to a remote GPS:

/usr/local/sbin/gpsd -N -D2 tcp://<IP>:<PORT>

Test the connection to gpsd with telnet localhost 2947 and send the string:

?WATCH={"enable":true,"json":true};