Failed example of sending data from Zenoh to ROS2DDS

main.rs

use byteorder::LittleEndian;
use cdr_encoding::from_bytes;
use serde::{Deserialize, Serialize};
use zenoh;


#[derive(Serialize, Deserialize, Debug, Default)]
struct Quaternion {
    x: f64,
    y: f64,
    z: f64,
    w: f64,
}

#[derive(Serialize, Deserialize, Debug, Default)]
struct Vector3 {
    x: f64,
    y: f64,
    z: f64,
}

#[derive(Serialize, Deserialize, Debug, Default)]
struct Time {
    sec: u32,
    nanosec: u32,
}

#[derive(Serialize, Deserialize, Debug, Default)]
struct Header {
    stamp: Time,
    frame_id: String,
}

// From: https://docs.ros2.org/foxy/api/sensor_msgs/msg/Imu.html
#[derive(Serialize, Deserialize, Debug, Default)]
struct Imu {
    header: Header,
    orientation: Quaternion,
    orientation_covariance: [f64; 9],
    angular_velocity: Vector3,
    angular_velocity_covariance: [f64; 9],
    linear_acceleration: Vector3,
    linear_acceleration_covariance: [f64; 9],
}

#[tokio::main]
async fn main() -> zenoh::Result<()> {
    let session = zenoh::open(zenoh::Config::default()).await?;

    let lv_ke = format!(
        "@/{}/@ros2_lv/MP/patrick§imu§data_raw/sensor_msgs::msg::Imu/:::",
        session.zid()
    );

    let sub = session.declare_subscriber("mavros/imu/data_raw").await?;
    while let Ok(sample) = sub.recv_async().await {
        let raw = sample.payload().to_bytes();
        session.put(&lv_ke, raw.clone()).await?;
        // Remove the CDR header, 2 bytes for endianness, 2 bytes for padding / reserved
        // Check 10.2: https://www.omg.org/spec/DDSI-RTPS/2.3/PDF
        let payload = &raw[4..];
        let (msg, _) = from_bytes::<Imu, LittleEndian>(payload).unwrap();
        println!("{msg:#?}");
    }
    Ok(())
}

Several errors to address:

• L.51: When declaring the equivalent of a ROS Subscriber, the liveliness token should contain /MS/ (for Msg Subscriber), not /MP/

• L.55: At the same time than you declare the Zenoh Subscriber, you should announce to the zenoh-bridge-ros2dds that it's a ROS Subscriber declaring the liveliness token as such:

  let token = session.liveliness().declare_token(lv_ke).await?;

• L.58: Calling session.put(&lv_ke, raw.clone()) is useless.