GPS binding API

The API exposed by the binding is : gps

The binding has been made for clients to subscribe to it, so it has only three verbs :

Verb Description
gps_data Get freshest data that came from GPSD
subscribe Subscribe to gps data with specific conditions
unsubscribe Unsubscribe to gps data with specific conditions


gps gps_data


  • Avalaible data :
    • gps_data
  • Available condition & value :
    • frequency (hz)
      • 1, 10, 20, 50, 100
    • movement (m)
      • 1, 10, 100, 300, 500, 1000
    • max_speed (km/h)
      • 20, 30, 50, 90, 110, 130
  • examples :

Get gps_data a 10Hz

gps subscribe {"data" : "gps_data", "condition" : "frequency", "value" : 10}

Get gps_data if there is a movement of at least 1 meter since last event

gps subscribe {"data" : "gps_data", "condition" : "movement", "value" : 1}

Get gps_data each time the speed exceeds 20 km/h

gps subscribe {"data" : "gps_data", "condition" : "max_speed", "value" : 20}

JSON Answer format

Wether it’s coming from a subscription or the direct call “gps_data” verb the structure of the answer is the same, values are rawly coming from the libgps, you can find a lot of information about them directly in this library.

Here is the answered JSON content :

Key Type Description
visible satellites Int Number of visible satellites
used satellites Int Number of satellites in used
mode Int Mode of fix (0 to 3)
latitude Double Latitude in degrees
longitude Double Longitude in degrees
speed Double Speed over ground, meters/sec
altitude Double Altitude in meters
climb Double Vertical speed, meters/sec
heading (true north) Double Course made good (relative to true north)
timestamp Double Standard timestamp

Each value from “Latitude” is also accompanied by its error value expressed in the same type and unit as this one. (ex : latitude error).

JSON example

ON-REPLY 1:gps/gps_data: OK
    "visible satellites":0,
    "used satellites":0,
    "latitude error":NaN,
    "longitude error":NaN,
    "speed error":NaN,
    "altitude error":23.0,
    "climb error":46.0,
    "heading (true north)":254.5,
    "heading error":NaN,
    "timestamp error":0.0050000000000000001
    "info":"GNSS location data"