Standard Messages

HORUS provides 60+ typed message types covering every common robotics domain. All messages support zero-copy shared memory transport via Topic<T>.

// simplified
use horus::prelude::*;

Which Message Do I Need?

I need to...	Use	Page
Send velocity commands to motors	`CmdVel`, `Twist`	Control
Read IMU data (accel + gyro)	`Imu`	Sensor
Read LiDAR scans	`LaserScan`	Sensor
Publish robot position	`Odometry`, `Pose2D`, `Pose3D`	Sensor, Geometry
Send camera images	`Image`	Image API
Send point clouds	`PointCloud`	PointCloud API
Report detections (ML output)	`Detection`, `Detection3D`	Perception
Send navigation goals	`NavGoal`, `NavPath`	Navigation
Report system health	`DiagnosticReport`, `NodeHeartbeat`	Diagnostics
Send force/torque data	`WrenchStamped`, `ForceCommand`	Force
Send joystick/keyboard input	`JoystickInput`, `KeyboardInput`	Input
Send audio data	`AudioFrame`	Audio
Send ML tensors	`Tensor`	Tensor API
Send dynamic/untyped data	`GenericMessage` (4KB, MessagePack)	GenericMessage

Message Categories

Category	Types	Page
Geometry	Twist, Pose2D, Pose3D, Point3, Vector3, Quaternion, TransformStamped, Accel	Geometry Messages
Sensor	Imu, LaserScan, Odometry, NavSatFix, BatteryState, JointState, Temperature, MagneticField	Sensor Messages
Control	CmdVel, MotorCommand, ServoCommand, PidConfig, DifferentialDriveCommand	Control Messages
Navigation	NavGoal, NavPath, Waypoint, OccupancyGrid, CostMap, VelocityObstacle	Navigation Messages
Perception	Detection, Detection3D, TrackedObject, SegmentationMask, LandmarkArray	Perception Messages
Vision	CompressedImage, CameraInfo, RegionOfInterest, StereoInfo, BoundingBox	Vision Messages
Diagnostics	DiagnosticReport, NodeHeartbeat, SafetyStatus, EmergencyStop	Diagnostics Messages
Force & Haptics	WrenchStamped, ForceCommand, ContactInfo, ImpedanceParameters	Force Messages
Input	JoystickInput, KeyboardInput	Input Messages
Clock	Clock-related messages	Clock Messages
ML	ML inference messages	ML Messages
Tensor	Tensor descriptors	Tensor Messages

Import

All standard messages are available via the prelude:

// simplified
use horus::prelude::*;

// Now you can use: CmdVel, Imu, Odometry, LaserScan, Twist, Pose2D, etc.
let cmd = CmdVel::new(1.0, 0.0);
let imu = Imu::new();

Custom Messages

Need a type that doesn't exist? Use the message! macro:

// simplified
use horus::prelude::*;

message! {
    MotorStatus {
        rpm: f32,
        current_amps: f32,
        temperature_c: f32,
        fault_code: u32,
    }
}

let topic = Topic::<MotorStatus>::new("motor.status")?;

See Macros for the full message! syntax.

Fixed-Size Types and Zero-Copy

All standard messages are #[repr(C)], Copy, and fixed-size — they transfer through shared memory without serialization. Variable-length data (images, point clouds, tensors) use pool-backed allocation instead.