Web UI

We created a simple web UI to monitor the rover’s vision and to implement a dead man’s switch.

The client-side of this system is simply the flat webui.html file in the same directory as this documentation file (ros/webui.html in the repo).

The server-side is implemented by the GCS WebUI WebSockets server ROS node.

Protocol

Communication is done over a single WebSocket connection using this simple schema:

{
    type: "<message type>",
    data: "<message data>"
}

type is one of:

  • RGB: RGB image from the camera (displayed on the left in the UI)

  • MASK: inferred path mask (displayed on the right in the UI)

  • PING: ping (explanation as to why this is necessary)

  • PONG: ping

  • DMS: dead man’s switch signal, indicates the GCS connection is still OK

  • STEER: actual steering data sent to the flight controller

  • OFFLOADED_INFERENCE: a path mask sent by the run_inference_ws.py script (see Offloaded inference for more info)

data is either a string or an object, depended upon the message type.

In case of an image message (RGB, MASK or OFFLOADED_INFERENCE), data is the base64 encoded raw png or jpeg image data.