How to Connect to SITL Using DroneKit: Simple Guide

To connect to SITL using dronekit, use connect() with the SITL connection string like 'tcp:127.0.0.1:5760'. This opens a vehicle object you can control programmatically.

Syntax

The basic syntax to connect to SITL with DroneKit is:

• connect(connection_string, wait_ready=True): Connects to the vehicle.
• connection_string: The address of SITL, e.g., 'tcp:127.0.0.1:5760' or 'udp:127.0.0.1:14550'.
• wait_ready: If True, waits until the vehicle is fully initialized.

python

from dronekit import connect

vehicle = connect('tcp:127.0.0.1:5760', wait_ready=True)

Example

This example shows how to start SITL, connect to it using DroneKit, print the vehicle's GPS status, and then close the connection.

python

from dronekit import connect, VehicleMode
import time
from dronekit_sitl import SITL

# Start SITL instance
sitl = SITL()
sitl.download('copter', '3.3', verbose=False)
sitl_args = ['-I0', '--model', 'quad']
sitl.launch(sitl_args, await_ready=True, restart=True)

# Connect to SITL
connection_string = 'tcp:127.0.0.1:5760'
vehicle = connect(connection_string, wait_ready=True)

# Print GPS status
print(f"GPS fix type: {vehicle.gps_0.fix_type}")

# Close vehicle object and stop SITL
vehicle.close()
sitl.stop()

Output

GPS fix type: 3

Common Pitfalls

Common mistakes when connecting to SITL with DroneKit include:

• Using the wrong connection string format or port.
• Not starting SITL before connecting.
• Forgetting to call vehicle.close() to clean up.
• Not waiting for the vehicle to be ready, causing attribute errors.

python

from dronekit import connect

# Wrong: Connecting before starting SITL or wrong port
# vehicle = connect('tcp:127.0.0.1:1234', wait_ready=True)  # Wrong port

# Right way:
vehicle = connect('tcp:127.0.0.1:5760', wait_ready=True)

# Always close connection
vehicle.close()

Quick Reference

Tips for connecting to SITL using DroneKit:

• Use tcp:127.0.0.1:5760 or udp:127.0.0.1:14550 as connection strings depending on SITL setup.
• Always start SITL before connecting.
• Use wait_ready=True to ensure vehicle is fully initialized.
• Close the vehicle connection with vehicle.close() when done.

Key Takeaways

Use the correct connection string like 'tcp:127.0.0.1:5760' to connect to SITL with DroneKit.

Always start the SITL simulator before attempting to connect.

Set wait_ready=True to ensure the vehicle is fully initialized before use.

Close the vehicle connection with vehicle.close() to free resources.

Check your connection string and ports carefully to avoid connection errors.