Telemetry
The communication between the UAV and GCS takes place by the transmission and reception of a defined set of messages, which are encoded using Mavlink. A custom Mavlink dialect is used to improve customization and reduce overhead caused by standardization.
The communication is divided into subprotocols, where each subprotocol specifies the sequence of interchanging and a subset of the total messages to meet a specific objective. Subprotocols are themselves loosely grouped into the following categories -
- Discovery & Connection - Handles discovery of system components (UAV, GCS) and connection lifecycle.
- State Transitions - Handles initiation and notification of state transitions in either of the three orthogonal states (activity, flight control mode and error).
- Input & Output Channels - Handles transmission of input and output channels (from RC and to motors/control-surfaces).
- Sensor & Pose Data - Handles transmission of raw sensor data and estimator pose.
- PID gains exhange - Handles exchange and synchronization of PID gains for the different controllers.
- Home Location - Handles exchange and synchronization of the Home Location.
- Geofence - Handles exchange and synchronization of the Geofence.
- Mission - Handles exchange and synchronization of the Mission.
- UAV Configuration - Handles exchange and synchronization of the UAV Configuration.