GPS Schema Example

Topic: /gps
Message: NavSatFix

This example will go through how to connect to the GPS topic published on your EdgeFirst Platform and how to display the information through the Rerun visualizer.

Setting up subscriber

After setting up the Zenoh session, we will create a subscriber to the rt/gps topic

PythonRust

# Create a subscriber for "rt/gps"
subscriber = session.declare_subscriber('rt/gps')

let subscriber = session
    .declare_subscriber("rt/gps")
    .await
    .unwrap();

Decode GPS Data

We can now recieve message on the subcriber that will be handled by the gps_listener function. After recieving the message, we will need to deserialize it.

PythonRust

from edgefirst.schemas.sensor_msgs import NavSatFix
msg = subscriber.recv()
gps = NavSatFix.deserialize(msg.payload.to_bytes())

use edgefirst_schemas::sensor_msgs::{NavSatFix};
msg = subscriber.recv()
let gps: NavSatFix = cdr::deserialize(&msg.payload().to_bytes())?;

Get Latitude/Longitude Values and Post to Rerun

We will now pull out the latitude/longitude data from the decoded NavSatFix message and log the data to Rerun.

PythonRust

lat = gps.latitude
long = gps.longitude
# print("Latitude: %.6f Longitude: %.6f" % (lat, long))
rr.log("Current Location", rr.GeoPoints(lat_lon=[lat, long]))

let lat = gps.latitude;
let long = gps.longitude;
// println!("Latitude: {} Longitude: {}",lat, long);
let _ = rec.log("CurrentLoc", &rerun::GeoPoints::from_lat_lon([(lat, long)]));

Results

The command line output will appear as the following

Latitude: 51.036506 Longitude: -114.034886
Latitude: 51.036506 Longitude: -114.034886
Latitude: 51.036506 Longitude: -114.034886

When displaying the results through Rerun you will see a map with the location of your EdgeFirst Platform marked. alt text