UWB Following Service Interface

UWB Raw Data Subscription Interface

Description

This interface is used to subscribe to the /uwb_data topic in ROS2 in order to receive coordinate data feedback from the UWB wristband.

Topic Name	Topic Type (Custom Message)	Role
/uwb_data	uwb_sensor_msgs::msg::UwbDataWithTimestamp	Subscriber

Message Structure

The message type uwb_sensor_msgs::msg::UwbDataWithTimestamp contains the following fields:

Field Name	Description
x_position	Represents the X-axis coordinate of the tag relative to the anchor, in centimeters (cm).
y_position	Represents the Y-axis coordinate of the tag relative to the anchor, in centimeters (cm).
distance	Represents the 2D Euclidean distance between the tag and the anchor, in centimeters (cm).
phase	Represents the angle (phase) of the tag relative to the anchor, in degrees (°).

Callback Example Message

void uwb_callback( 
    const uwb_sensor_msgs::msg::UwbDataWithTimestamp::SharedPtr msg) {
    if(msg->distance ==0 && msg->phase ==0 )
    {
        uwb_updated_ = false;
    }else
    {
        msg->distance = (msg->distance)*0.01;

        RCLCPP_INFO(this->get_logger(),
        "Received UWB data: dis: '%f m', phase: '%f deg'",
        msg->distance, msg->phase);
    }
}

Testing Method

• To print UWB topic /uwb_data in real time, use the following command in the terminal:

ros2 topic echo /uwb_data

• To analyze the publishing frequency of the UWB data in real time, use:

ros2 topic hz /uwb_data

Precautions

If the output shows error messages or remains empty, it is most likely due to the custom message type not being part of the standard ROS 2 library. Before running the above commands, make sure to source the workspace:

source install/setup.bash