Can't connect to drone from laptop using MAVSDK

luisdelavega · 3 Apr 2025, 14:37

I've got a Starling Max 2 (VOXL2) connected to my home network. My laptop is also connected to that same network. I'm trying to connect to the drone using MAVSDK-Python but it just doesn't work. I've lost count of everything I've tried, nothing related to MAVSDK has worked for me.

I've updated the configuration file’s primary_static_gcs_ip field at /etc/modalai/voxl-mavlink-server.conf to my laptops IP address.

I'm able to connect with it using pymavlink. I can adb shell in and see the messages coming in by running voxl-inspect-mavlink mavlink_from_gcs. But like I said, MAVSDK just does not connect to the VOXL2...

Here's an actual snippet I'm trying to run:

#!/usr/bin/env python3

import asyncio
import time
from mavsdk import System
from pymavlink import mavutil

async def send_heartbeat_and_param_requests(target_ip="192.168.1.187", target_port=14550):
    """Send MAVLink heartbeats and parameter requests to initiate connection with VOXL2"""
    print(f"Sending heartbeats to {target_ip}:{target_port}")
    
    # Create a UDP connection to VOXL2
    connection = mavutil.mavlink_connection(f'udpout:{target_ip}:{target_port}')
    
    # Important: Set specific system and component IDs
    # System ID should not be 1 (typically the vehicle) or 255
    # Component ID should NOT be 0 as that's invalid for a source
    connection.source_system = 2       # Use 2 for a secondary GCS
    connection.source_component = 1    # Use 1 for autopilot component
    
    # Send heartbeats in a loop
    counter = 0
    while True:
        # Send a heartbeat message
        connection.mav.heartbeat_send(
            mavutil.mavlink.MAV_TYPE_GCS,              # Type: Ground Control Station
            mavutil.mavlink.MAV_AUTOPILOT_INVALID,     # Autopilot type
            0,                                          # Base mode
            0,                                          # Custom mode
            mavutil.mavlink.MAV_STATE_ACTIVE           # System status
        )
        
        counter += 1
        if counter % 5 == 0:  # Every 5 seconds
            # Send a parameter request list (this is what QGC does on connection)
            connection.mav.param_request_list_send(
                1,     # Target system (default autopilot is usually 1)
                190    # Target component (default autopilot component)
            )
            
            # Send a ping message
            connection.mav.ping_send(
                int(time.time() * 1000),  # Unix timestamp in milliseconds
                0,                         # Sequence
                connection.source_system,  # System ID
                connection.source_component # Component ID
            )
        
        print(f"Heartbeat sent (count: {counter})")
        await asyncio.sleep(1)  # Send heartbeats at 1Hz

async def connect_to_drone():
    print("Connecting to VOXL2...")
    
    drone = System()
    
    # Different connection string formats to try
    await drone.connect(system_address="udp://:14550")
    
    print("Waiting for drone to connect...")
    timeout = 60  # Extended timeout
    start_time = asyncio.get_event_loop().time()
    
    try:
        async for state in drone.core.connection_state():
            print(f"Connection state: {state}")
            
            if state.is_connected:
                print(f"Connected to drone!")
                return drone
            
            # Check if we've timed out
            current_time = asyncio.get_event_loop().time()
            if current_time - start_time > timeout:
                print(f"Connection timed out after {timeout} seconds")
                break
                
            await asyncio.sleep(1)
            
    except Exception as e:
        print(f"Connection error: {e}")
    
    return None

async def main():
    # Start sending heartbeats in the background
    heartbeat_task = asyncio.create_task(send_heartbeat_and_param_requests())
    
    # Wait to ensure heartbeats are being received
    await asyncio.sleep(5)
    
    # Try to connect to the drone
    drone = await connect_to_drone()
    
    # If connected, do something with the drone
    if drone and drone.core:
        try:
            # Print basic information
            info = await drone.info.get_version()
            print(f"Version Info: {info}")
        except Exception as e:
            print(f"Could not get info: {e}")
    
    # Clean up the heartbeat task
    heartbeat_task.cancel()
    try:
        await heartbeat_task
    except asyncio.CancelledError:
        print("Heartbeat task cancelled")

if __name__ == "__main__":
    # Run the asyncio loop
    asyncio.run(main())

It never even gets to print out the "Waiting for drone to connect..." mesage. The code doesn't execute past the await drone.connect(system_address="udp://:14550") line.

For the await drone.connect(system_address="udp://:14550") line I've tried every permutation I've found. With or without the VOXL2 IP address. I've used udpout and all other variants, none work.

I've tried with and without sending the messages using pymavlink in case there is some conflict.

I've tried connecting with specific sysid and compid like below:

# Create a System object with specific system ID and component ID
# These match the IDs we're using in the heartbeat sender
drone = System(sysid=2, compid=1)

I don't know what else to do. Any help will be greatly appreciated.

luisdelavega · 3 Apr 2025, 15:35

UPDATE

I've simplified my snippet and I'm now able to "connect" to the VOXL2 via MAVSDK. It's still now working as I would expect it to, but first, here's my new script:

#!/usr/bin/env python3

import asyncio
from mavsdk import System

target_ip="192.168.1.187"
target_port=14550

async def connect_to_drone():
    print("Connecting to VOXL2...")
    
    # Create a System object with specific system ID and component ID
    # These match the IDs we're using in the heartbeat sender
    print("Creating System object...")
    drone = System()
    
    # Different connection string formats to try
    print("Connecting to drone...")
    await drone.connect(system_address=f"udp://{target_ip}:{target_port}")
    
    print("Waiting for drone to connect...")
    timeout = 60  # Extended timeout
    start_time = asyncio.get_event_loop().time()
    
    try:
        async for state in drone.core.connection_state():
            print(f"Connection state: {state}")
            
            if state.is_connected:
                print(f"Connected to drone!")
                return drone
            
            # Check if we've timed out
            current_time = asyncio.get_event_loop().time()
            if current_time - start_time > timeout:
                print(f"Connection timed out after {timeout} seconds")
                break
                
            await asyncio.sleep(1)
            
    except Exception as e:
        print(f"Connection error: {e}")
    
    return None

async def main():
    # Try to connect to the drone
    drone = await connect_to_drone()
    
    # If connected, do something with the drone
    if drone and drone.core:
        try:
            # Print basic information
            info = await drone.info.get_version()
            print(f"Version Info: {info}")
        except Exception as e:
            print(f"Could not get info: {e}")

if __name__ == "__main__":
    # Run the asyncio loop
    asyncio.run(main())

When I run this script I see only 3 logs:

Connecting to VOXL2...
Creating System object...
Connecting to drone...

When I adb shell and run voxl-inspect-mavlink mavlink_from_gcs I now see that the VOXL2 is receiving a heartbeat:

ID	Mavlink MSG Name	Counter	Hz
0	heartbeat	5	1.1

But like I mentioned above, the code doesn't execute past await drone.connect(system_address=f"udp://{target_ip}:{target_port}").

I've tried udpout and nothing changes.