Package frc.lib.lowlevel

Class Whacknet

java.lang.Object

frc.lib.lowlevel.Whacknet

All Implemented Interfaces:

AutoCloseable

public class Whacknet
extends Object
implements AutoCloseable

Pure Java implementation of the Whacknet UDP Vision Protocol.

Handles high-frequency vision data from coprocessors and broadcasts robot telemetry. Uses Direct ByteBuffers and the Flyweight pattern to achieve zero-allocation performance, avoiding Garbage Collector pressure during matches.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	Whacknet.PacketView	Zero-allocation view into the ByteBuffer representing a single Vision Observation.
static final record	Whacknet.RobotTelemetry	A record representing the robot's telemetry data.

Method Summary

Modifier and Type	Method	Description
void	broadcastTelemetry(long timestamp, double roll, double pitch, double yaw, double rollVel, double pitchVel, double yawVel, int port)	Broadcasts robot telemetry to the vision coprocessor for constrained pose solving.
void	close()	Gracefully shuts down the Whacknet server, freeing UDP ports and stopping the receiver thread.
void	forEachPacket(ObjIntConsumer<Whacknet.PacketView> consumer)	Iterates over packets received since the last call to readPackets().
static Whacknet	getInstance()	Returns the singleton instance of Whacknet.
int	readPackets()	Drains the internal ring buffer into a snapshot buffer for the main loop to process.
void	registerTelemetryService(int port, Frequency frequency, Supplier<Whacknet.RobotTelemetry> supplier)	Registers a service to broadcast robot telemetry at a specified frequency.
void	startServer(int port)	Starts the vision server to receive observations from coprocessors.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

getInstance

public static Whacknet getInstance()

Returns the singleton instance of Whacknet.

Returns:

The Whacknet instance.

startServer

public void startServer(int port)

Starts the vision server to receive observations from coprocessors.

Parameters:

port - The UDP port to listen on.

broadcastTelemetry

public void broadcastTelemetry(long timestamp,
 double roll,
 double pitch,
 double yaw,
 double rollVel,
 double pitchVel,
 double yawVel,
 int port)

Broadcasts robot telemetry to the vision coprocessor for constrained pose solving.

Parameters:

timestamp - FPGA timestamp in microseconds.

roll - Robot roll in radians.

pitch - Robot pitch in radians.

yaw - Robot yaw in radians.

rollVel - Roll velocity in radians per second.

pitchVel - Pitch velocity in radians per second.

yawVel - Yaw velocity in radians per second.

port - The UDP port to broadcast on.

registerTelemetryService

public void registerTelemetryService(int port,
 Frequency frequency,
 Supplier<Whacknet.RobotTelemetry> supplier)

Registers a service to broadcast robot telemetry at a specified frequency. Clears the old notifier if it exists. If the consumer is not null, it will be used to process the telemetry data.

Parameters:

port - The UDP port to broadcast on.

frequency - The frequency at which to broadcast.

supplier - A supplier for obtaining robot telemetry data.

readPackets

public int readPackets()

Drains the internal ring buffer into a snapshot buffer for the main loop to process.

Returns:

The number of packets available to process this frame.

close

public void close()

Gracefully shuts down the Whacknet server, freeing UDP ports and stopping the receiver thread.

Specified by:

close in interface AutoCloseable

forEachPacket

public void forEachPacket(ObjIntConsumer<Whacknet.PacketView> consumer)

Iterates over packets received since the last call to readPackets().

Parameters:

consumer - A lambda to process each packet view.