Telemetry streamer

Nodes: ghanta nav sim com | Module: telemetry | Parameters: Telemetry

The module provides telemetry stream management.

See the source code for implementation details.

Data flow

In the common scenario, the telemetry stream should be generated in one node, where the most of data is available, and usually it is nav node. The module collects all mandala values from the network and local node modules, assembles values to a tightly packed data stream and transmits it to the network. The com node in the same network receives the telemetry packet, wraps it to the identity and transmits vehicle.downlink packet to the GCS.

The telemetry module collects mandala values only when they are available for the node, it does not explicitly subscribe for any mandala field.

Another example would be when you want to receive some measurements from the GCS ground modem or tracking antenna. F.ex., you need ground modem battery voltage in the GCS instruments. For such scenario, the configured ground modem node (com) with its identity will have telemetry module configured as mode=always, rate=1Hz for the GCS to receive all ground modem data once a second.

Configuration parameters

  • Telemetry

    Telemetry data stream

    • mode Stream mode option [off,auto,always]
      • auto: the stream will be sent to GCS upon reception of telemetry requests from the GCS, i.e. when the vehicle is active and selected on the GCS UI. When there’s no requests from GCS - the module will send just short XPDR data packets to the GCS once a second;
      • always: the telemetry stream will always be set, regardless of uplink availability and GCS requests;
    • rate Stream packets rate option [10Hz,1Hz,5Hz,20Hz,50Hz]

      10Hz is the default and used for the most cases.

    • broadcast Broadcast to all interfaces option

      Normally, the telemetry stream will be sent to the only node interface to optimize bandwidth, to be later transmitted by com node to the GCS. The interface is detected automatically based on requests routes from the GCS. In case you have to forward telemetry stream to other redundant modems (f.ex. connected to a VCP), this option should be turned on to make data broadcasted and available to other modules/nodes.

    • data

      To limit the bandwidth, stream can have included (or excluded) specific variable groups. See source code for details.

      • mode Default dataset selection option [default,minimal,normal,none]
        • default: autopilot telemetry dataset, used for experimental flights;
        • minimal: minimal vehicle telemetry;
        • normal: same as default dataset with some values removed, enough for normal operation;
        • none: no data fields selected;
      • sync Auto add modified data fields option
      • usr User related data option
      • srcs Redundancy of sensors option
      • cam Gimbal payload related data option
      • ats Tracking antenna related data option
      • turret Turret related data option
      • haps Haps related data option
      • aux bind

        Auxillary mandala variables to be included in the stream.