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Nectar Interfaces

Custom ROS2 message definitions for the Nectar SDK.

Overview

This package provides custom ROS2 message types used by vision and control modules to publish detection results and sensor data.

Messages

ArucoTransforms

ArUco marker pose estimation data.

File: msg/ArucoTransforms.msg

int32 id
geometry_msgs/Vector3 translation
std_msgs/Float64 yaw
Field Type Description
id int32 Detected marker ID
translation geometry_msgs/Vector3 3D position relative to camera (meters)
yaw std_msgs/Float64 Marker rotation angle (degrees, 0-360)

Published by: ArucoNode · Topic: /aruco/pose_estimate

LineInfo

Line detection state information.

File: msg/LineInfo.msg

float64 center_x
float64 center_y
float64 angle
float64 width
float64 height
Field Type Description
center_x float64 Line center X coordinate (pixels)
center_y float64 Line center Y coordinate (pixels)
angle float64 Line angle (degrees, -90 to +90)
width float64 Average line width (pixels)
height float64 Average line height (pixels)

Published by: LineDetectionNode · Topic: line_state/{color} (e.g. line_state/blue)

PhotoInfo

Photo metadata with coordinates.

File: msg/PhotoInfo.msg

float64[] coordinates
string photo_num
Field Type Description
coordinates float64[] Array of coordinate values
photo_num string Photo identifier/number

Dependencies

Package Description
geometry_msgs Standard ROS2 geometry message types (Vector3)
std_msgs Standard ROS2 message types (Float64)
rosidl_default_generators ROS2 IDL code generation

Building

The package is built automatically with the workspace:

cd ~/ros2_ws
colcon build --packages-select nectar_interfaces
source install/setup.bash

Verify:

ros2 interface list | grep nectar_interfaces
ros2 interface show nectar_interfaces/msg/ArucoTransforms

Usage

Python — import, publish, and subscribe:

from nectar_interfaces.msg import ArucoTransforms, LineInfo, PhotoInfo
from geometry_msgs.msg import Vector3
from std_msgs.msg import Float64

# Publisher
pub = node.create_publisher(ArucoTransforms, '/aruco/pose_estimate', 10)
msg = ArucoTransforms()
msg.id = 42
msg.translation = Vector3(x=0.5, y=0.1, z=1.2)
msg.yaw = Float64(data=45.0)
pub.publish(msg)

# Subscriber
def on_aruco(msg: ArucoTransforms):
    print(f"Marker {msg.id} at ({msg.translation.x:.2f}, {msg.translation.y:.2f}, {msg.translation.z:.2f}) m")

node.create_subscription(ArucoTransforms, '/aruco/pose_estimate', on_aruco, 10)

C++:

#include "nectar_interfaces/msg/aruco_transforms.hpp"

auto pub = node->create_publisher<nectar_interfaces::msg::ArucoTransforms>(
    "/aruco/pose_estimate", 10);
  • Vision Module — camera drivers and algorithms that publish these messages
  • Vision Nodes — ROS 2 nodes using these interfaces

References