IMU Schema Example

Topic: /imu
Message: Imu

This example will go through how to connect to the IMU topic published on your EdgeFirst Platform and how to display the information through the Rerun visualizer.

Setting up subscriber

After setting up the Zenoh session, we will create a subscriber to the rt/imu topic

PythonRust

# Log the initial orientation
rr.log("/imu", rr.Boxes3D(half_sizes=[[0.5, 0.5, 0.5]], fill_mode="solid"))
rr.log("/imu", rr.Transform3D(axis_length=2))

# Create a subscriber for "rt/imu"
loop = asyncio.get_running_loop()
drain = MessageDrain(loop)
session.declare_subscriber('rt/imu', drain.callback)

let subscriber = session
    .declare_subscriber("rt/imu")
    .await
    .unwrap();

Receive the Message

We can now receive message on the subscriber. After receiving the message, we will need to deserialize it.

PythonRust

async def imu_handler(drain):
    while True:
        msg = await drain.get_latest()
        thread = threading.Thread(target=imu_worker, args=[msg])
        thread.start()

        while thread.is_alive():
            await asyncio.sleep(0.001)
        thread.join()

use edgefirst_schemas::sensor_msgs::{IMU};
while let Ok(msg) = subscriber.recv() {
    let imu: IMU = cdr::deserialize(&msg.payload().to_bytes())?;
}

Process the IMU Data

We will now pull out the IMU data from the decoded Imu message and send the quaternion to Rerun.

PythonRust

def imu_worker(msg):
    imu = Imu.deserialize(msg.payload.to_bytes())
    x = imu.orientation.x
    y = imu.orientation.y
    z = imu.orientation.z
    w = imu.orientation.w
    rr.log("/imu",
            rr.Transform3D(clear=False,
                            quaternion=Quaternion(xyzw=[x, y, z, w])))

let x = imu.orientation.x as f32;
let y = imu.orientation.y as f32;
let z = imu.orientation.z as f32;
let w = imu.orientation.w as f32;
// println!("X: {} Y: {} Z: {} W: {}", x, y, z, w);
let my_quat = rerun::Quaternion([x,y,z,w]);
let _ = rec.log("box", &rerun::Transform3D::default().with_quaternion(my_quat));

Results

The command line output will appear as the following

X: -0.0125 Y: 0.0383 Z: 0.0698 W: 0.9968
X: -0.0125 Y: 0.0383 Z: 0.0698 W: 0.9968
X: -0.0125 Y: 0.0383 Z: 0.0698 W: 0.9968

When displaying the results through Rerun you will see a solid cube that is matching the orientation of your EdgeFirst Platform alt text