Here are the classes, structs, unions and interfaces with brief descriptions:

[detail level 123456]

▼Nupkie	Software for wheeled-biped robots
▼Ncontrollers	Functions and classes related to balance control
▼Nmpc_balancer	Wheel balancing by model predictive control
►Nmpc_balancer
CMPCBalancer	Model-predictive control sagittal balancer
►Nproxqp_workspace
CProxQPWorkspace	Workspace data for ProxQP
▼Ncpp	C++ library to create new spines
▼Nexceptions	Exceptions raised by this project
CControllerError	Exception thrown when a controller fails
CFilterError	Exception for filter errors
CObserverError	Exception thrown when an observer fails
CPositionCommandError	Exception raised when an actuation command is incorrect
CServoError	Exception for filter errors
CTypeError	Exception raised when a deserialized object does not have the right type
CUpkieError	Base class for Upkie-related exceptions
▼Ninterfaces	Send actions to actuators or simulators
►Nbullet	Bullet utility functions used in the simulation interface
CContactData	Contact information for a single link
CExternalForce	Parameters for a call to Bullet's applyExternalForce
CJointProperties	Properties for robot joints in the Bullet simulation
CRobotSimulatorChangeDynamicsArgs	Structure which contains the new link properties
CRobotSimulatorClientAPI	Child class to enable modification of inertia matrices
►Nmoteus	Interface to moteus controllers used in pi3hat spines
CCanFrame	CAN frame data structure for the moteus protocol
CData	Data for one control cycle
CMultiplexParser	Parser for multiplex data in the moteus protocol
COutput	Output information forwarded to an interface's callback function
CPositionCommand	Position command
CPositionResolution	Resolution settings for position control commands
CQueryCommand	Resolution settings for query commands
CQueryResult	Result data from moteus query commands
CServoCommand	Command sent to a servo
CServoReply	Reply from servo
CSpan	Fixed-size array with runtime size information
CWriteCanFrame	Writer for CAN frame data in the moteus protocol
CWriteCombiner	Groups registers when encoding them to minimize the required bytes
►CBulletInterface	Actuation interface for the Bullet simulator
CParameters	Interface parameters
CImuData	Data from the onboard inertial measurement unit (IMU)
CImuUncertainty	Uncertainty on IMU measurements
CInterface	Base class for actuation interfaces
CMockInterface	Interface whose internal state perfectly tracks commands
CPi3HatInterface	Interface to moteus controllers
CServoLayout	Map between servos, their busses and the joints they actuate
CServoProperties	Servo properties
▼Nobservers	State observers available for Upkies
►CBaseOrientation	Observe the orientation of the base frame relative to the world frame
CParameters	Parameters for the base orientation observer
►CFloorContact	Observe contact between the wheels and the floor
CParameters	Parameters to the floor contact observer
CHistoryObserver	Report high-frequency history vectors to lower-frequency agents
CObserver	Base class for observers
CObserverPipeline	Observer pipeline
►CWheelContact	Observe contact between a given wheel and the floor
CParameters	Observer parameters
►CWheelOdometry	Observe the relative motion of the floating base with respect to the floor
CParameters	Observer parameters
▼Nsensors	Sensors (pure outputs) available for Upkies
CCpuTemperature	Sensor for CPU temperature readings
CJoystick	Sensor for a joystick controller
CKeyboard	Sensor for reading Keyboard inputs
CSensor	Base class for sensors
CSensorPipeline	Sensor pipeline
▼Nspine	Inter-process communication protocol with the spine
CAgentInterface	Memory map to shared memory
►CSpine	Loop transmitting actions to the actuation and observations to the agent
CParameters	Spine parameters
CStateMachine	Spine state machine
▼Nutils	Utility functions
CSynchronousClock	Synchronous (blocking) clock
▼Nenvs	Gymnasium environments
▼Nbackends	Backend implementations for Upkie environments
►Nbackend	Interface to a backend for Upkie environments
CBackend	Interface to a backend for Upkie environments
►Ngenesis_backend	Backend using the Genesis physics simulator
CGenesisBackend	Backend using the Genesis physics simulator
►Nmock_backend	Backend that mimics perfect commands for testing
CMockBackend	Backend that mimics perfect commands for testing
►Npybullet_backend	Backend using PyBullet physics simulation
CPyBulletBackend	Backend using PyBullet physics simulation
►Nspine	Python interface to interact with a spine
►Nspine_interface
CSpineInterface	Interface to interact with a spine from a Python agent
►Nspine_backend	Backend connected to a simulation or real spine
CSpineBackend	Backend connected to a simulation or real spine
▼Ntesting
CActionObserverEnv	Test environment that returns the action as observation
CConstantObservationEnv	Test environment that returns a constant observation
CMockSpine	Mock spine interface for testing Upkie environments
▼Nupkie_env	Base class with features shared by all Upkie environments
CUpkieEnv	Base class with features shared by all Upkie environments
▼Nupkie_pendulum	Environment where Upkie behaves like a wheeled inverted pendulum
CUpkiePendulum	Wrapper to make Upkie act as a wheeled inverted pendulum
▼Nupkie_servos	Upkie environment where actions command servomotors directly
CUpkieServos	Upkie environment where actions command servomotors directly
▼Nwrappers	Wrappers to modify Gymnasium environments
►Nadd_action_to_observation	Append last action vector to the observation vector
CAddActionToObservation	Append last action vector to the observation vector
►Nadd_lag_to_action	Model lag as a low-pass filter on the action of an environment
CAddLagToAction	Model lag by applying a low-pass filter to the action of an environment
►Ndifferentiate_action	Act on the derivative of the action
CDifferentiateAction	Act on the derivative of the action
►Nnoisify_action	Add noise to the action of an environment
CNoisifyAction	Add noise to the action of an environment
►Nnoisify_observation	Add noise to the observation of an environment
CNoisifyObservation	Add noise to the observation of an environment
►Nrandom_push	Apply a random push at each step with a given probability
CRandomPush	At each step, with a given probability, apply a random push to the robot
▼Nexceptions	Exceptions raised by the Python library
CFallDetected	Raised when a fall is detected
CMissingOptionalDependency	Raised when an optional feature lacks a corresponding optional dependency
CModelError	Raised when something is wrong in the robot model
CPerformanceIssue	Raised when a performance issue is detected
CSpineError	Raised when the spine sets an error flag
CUpkieException	Base class for exceptions raised by Upkie agents
CUpkieRuntimeError	Runtime error, for instance an invalid call to a library function
CUpkieTimeoutError	Raised when something times out, typically the spine not responding
▼Nlogging	Custom logging formatter and logger for the library
CSpdlogFormatter	Custom logging formatter visually consistent with spdlog
▼Nmodel	Robot model parsed from its URDF description
▼Njoint
CJoint	Joint properties (see also joint limits)
▼Njoint_limit
CJointLimit	Joint limit in configuration and tangent spaces
▼Nmodel
CModel	Robot model parsed from its URDF description
▼Nutils	Utility functions
▼Njoystick	Joystick class used by mock spines to mimick the C++ Joystick sensor
CJoystick	Joystick class used by mock spines to mimick the C++ Joystick sensor
▼Nrobot_state	Robot state with optional randomization
CRobotState	Robot state (configuration and velocity) with optional randomization
▼Nrobot_state_randomization	Domain randomization of robot states
CRobotStateRandomization	Domain randomization parameters for Upkie's state