Telemetry

Telemetry (TCP Socket — Port 8081)

Continuous newline-delimited JSON stream. Connect and read; the app pushes updates automatically.

Telemetry fields:

Field	Type	Description
droneName	string	Drone name (set via app UI)
speed	{x, y, z}	Velocity (m/s)
heading	float	Compass heading (degrees)
attitude	{pitch, roll, yaw}	Aircraft attitude (degrees)
location	{latitude, longitude, altitude}	GPS position
phoneLocation	{latitude, longitude, heading, pressure, battery, wifiRssi}	Operator phone/RC location and sensor data
gimbalAttitude	{pitch, roll, yaw}	Gimbal orientation (degrees)
gimbalJointAttitude	{pitch, roll, yaw}	Gimbal joint angles (degrees)
zoomRatio	float	Camera zoom ratio
zoomFl / hybridFl / opticalFl	float	Focal lengths (-1 if unavailable)
batteryLevel	int	Battery % (0–100)
satelliteCount	int	GPS satellite count
homeLocation	{latitude, longitude}	Home point coordinates
homeSet	bool	Home point set
distanceToHome	float	Distance to home (m)
waypointReached	bool	Final waypoint reached
waypointSeq / yawSeq / altitudeSeq	int	Sequence id of the waypoint / yaw / altitude command currently being executed. Match against the seq returned by the command to avoid acting on a stale reach flag
intermediaryWaypointReached	bool	Intermediate waypoint reached
yawReached	bool	Target yaw reached
altitudeReached	bool	Target altitude reached
isRecording	bool	Camera recording active
flightMode	string	GPS / ATTI / VIRTUAL_STICK / GO_HOME / AUTO_LANDING / WAYPOINT / MANUAL
remainingFlightTime	int	Remaining flight time (s)
timeNeededToGoHome	float	Time to return home (s)
timeNeededToLand	float	Time to land (s)
totalTime	float	Go-home + land time (s)
maxRadiusCanFlyAndGoHome	float	Max safe flyable radius (m)
batteryNeededToGoHome	float	Battery % needed for RTH
batteryNeededToLand	float	Battery % needed to land
remainingCharge	int	Raw remaining battery charge from SDK
seriousLowBatteryThreshold	float	Critical low battery %
lowBatteryThreshold	float	Low battery warning %
isManualOverrideActive	bool	Pilot has taken manual RC control
readyToTakeoff	bool	All preflight conditions satisfied
takeoffBlockReason	string	Why takeoff is blocked when readyToTakeoff is false
lrfTarget	{latitude, longitude, altitude}	Last geo-referenced laser rangefinder target, null until the laser locks
autoSensingActive	bool	On-device target detection running
detectedTargets	array	Detected targets from auto-sensing
webRtc	object	WHIP/WebRTC sender state, FPS, processing, drop, error, bitrate, and recovery metrics when video is active; activeCamera and scaleMode identify the surface path

Reading video metrics

The webRtc object lets the dashboard distinguish a source/encoder problem from a network problem:

Field	Meaning
activeCamera	surface for the experimental DJI-to-MediaCodec path; the standard path reports its active DJI/phone/mock source
scaleMode	surface when MediaCodec receives the DJI surface directly; native or fixed for the regular frame-source path
inputFps / outputFps	Frames entering and leaving the sender path
totalDroppedFrames / droppedFps	Frames discarded by source pacing or backpressure
qualityLimitationReason	WebRTC’s sender-side reason for limiting quality, when reported by the platform
framesEncodedNotSent	Encoded frames waiting behind the network sender
sendBitrateBps	Approximate outbound WebRTC bitrate
recoveryCount	Number of source-pipeline recovery attempts, including keyframe recovery after queue pressure

On the surface path, a rising recoveryCount, falling outputFps, or non-zero framesEncodedNotSent is a reason to compare the same run with lb_whip_surface_h264_encoder=false. The comparison keeps the WHIP, MediaMTX, and browser path constant while changing only the camera-to-encoder stage.

Drone Identity & Auto-Discovery

• Custom naming: Set the drone name and its MAVLink vehicle ID via the app UI (tap the name/ID display or the settings entry). Examples: "RedScout", "Bravo".
• UDP broadcast discovery: DJIInterface("") broadcasts DISCOVER_LYREBIRD on port 30000; the app replies LYREBIRD_HERE:{ip}.
• UDP multicast discovery: The app announces over 239.255.42.99:30001 for LANs where multicast is available.
• mDNS/Bonjour: Lyrebird advertises _lyrebird._tcp. with service metadata.
• Config endpoint: /config returns drone name and connection metadata (used by ROS auto-discovery and the dashboard).
• Dynamic ROS namespaces: Nodes launch under the drone’s name (e.g., /RedScout/location), eliminating manual IP-to-name mapping.