Requesting data via mavlink

help
1

I'm new to Rust.
I want to retrieve pitch and roll data from a flight controller via MAVLink.
I copied a program that lets me display this data using the print function.
Here is the program:

use mavlink::error::MessageReadError;
use mavlink::MavConnection;
use std::{env, sync::Arc, thread, time::Duration};

fn main() {
let mut mavconn = mavlink::connect::mavlink::ardupilotmega::MavMessage("serial:/dev/ttyS2:500000").unwrap();
mavconn.set_protocol_version(mavlink::MavlinkVersion::V2);

let vehicle = Arc::new(mavconn);

vehicle
    .send(&mavlink::MavHeader::default(), &request_data())
    .unwrap();

loop {
    match vehicle.recv() {
        Ok((_header, msg)) => {
            println!("received: {msg:?}");
            //println!("{}", msg);
            //println!("pitch: {}", attitude);
        }

        Err(MessageReadError::Io(e)) => {
            if e.kind() == std::io::ErrorKind::WouldBlock {
                //no messages currently available to receive -- wait a while
                thread::sleep(Duration::from_secs(1));
                continue;
            } else {
                println!("recv error: {e:?}");
                break;
            }
        }
        _ => {}
    }
}

}

/// Create a message enabling command_long_data
pub fn request_data() -> mavlink::ardupilotmega::MavMessage {
mavlink::ardupilotmega::MavMessage::COMMAND_LONG(
mavlink::ardupilotmega::COMMAND_LONG_DATA {
param1 : 30.0,
param2 : 20000.0,
param3 : 0.0,
param4 : 0.0,
param5 : 0.0,
param6 : 0.0,
param7 : 0.0,
command : mavlink::ardupilotmega::MavCmd::MAV_CMD_SET_MESSAGE_INTERVAL,
target_system: 1,
target_component: 0,
confirmation: 0,
},
)
}

Here is the result on my screen :

received: ATTITUDE(ATTITUDE_DATA { time_boot_ms: 48198, roll: 0.027933115, pitch: -0.019092046, yaw: 1.0921404, rollspeed: -0.00025783258, pitchspeed: -0.00036752608, yawspeed: 0.00013963185 })
received: ATTITUDE(ATTITUDE_DATA { time_boot_ms: 48217, roll: 0.027932042, pitch: -0.019089786, yaw: 1.0921417, rollspeed: -0.00011153106, pitchspeed: -0.00022060832, yawspeed: -0.00023562514 })
received: ATTITUDE(ATTITUDE_DATA { time_boot_ms: 48237, roll: 0.027932605, pitch: -0.019088112, yaw: 1.0921559, rollspeed: -8.973977e-5, pitchspeed: -0.00029933767, yawspeed: 5.7152065e-5 })
received: ATTITUDE(ATTITUDE_DATA { time_boot_ms: 48257, roll: 0.02793914, pitch: -0.01909101, yaw: 1.0921576, rollspeed: 0.00042133417, pitchspeed: -0.00045995237, yawspeed: -9.257565e-5 })
received: ATTITUDE(ATTITUDE_DATA { time_boot_ms: 48277, roll: 0.0279463, pitch: -0.019081376, yaw: 1.0921631, rollspeed: 0.00019980557, pitchspeed: -0.00014700776, yawspeed: -0.00013636192 })

But I'd like to retrieve only the pitch and roll values as variables so I can use them later to display an artificial horizon.

Can you help me?

Thank you

​​​Reply

2

What is the type of msg ???

It's probably a struct that has functions to access internal fields like "pitch", etc.

BTW: You probably want to use cargo fmt to format your code.

3 
match msg {
    mavlink::ardupilotmega::MavMessage::ATTITUDE(
        mavlink::ardupilotmega::ATTITUDE_DATA {
            roll,
            pitch,
            ..
        }
    ) => {
        println!("roll: {roll}, pitch: {pitch}");
    }

    _ => {}
}
4

It's a miracle—it works!
Here's the result on my screen:

roll: 0.039741054, pitch: -0.015719308
roll: 0.039747275, pitch: -0.015701864
roll: 0.03974411, pitch: -0.015694147
roll: 0.039736528, pitch: -0.015685942
roll: 0.039722808, pitch: -0.015683198

A big thank you to you.

5

It is customary to mark the reply that gave you the answer as the solution to the topic, to give the poster credit. But it is up to you of course.

6

i'm sorry, but i'm not very familiar with this forum.

i'll make sure to mention that it was Jesper who gave me the solution

7

You can check the box at the bottom of @Jesper 's post to mark that post as the solution.

8

Thanks for the advice.

It's done.