How to Make a Drone Follow GPS Waypoints Easily

To make a drone follow GPS waypoints, you program it to navigate through a list of latitude and longitude coordinates using a flight controller API or SDK. The drone reads each waypoint and moves to it sequentially, adjusting its position using GPS data and onboard sensors.

Syntax

The basic syntax involves defining a list of GPS waypoints and sending them to the drone's navigation system. Each waypoint is a coordinate with latitude, longitude, and optionally altitude. The drone's API usually provides a method like go_to_waypoint() or mission_upload() to set these points.

• waypoints: List of GPS coordinates (latitude, longitude, altitude)
• upload_mission(): Sends waypoints to the drone
• start_mission(): Commands drone to begin following waypoints

python

waypoints = [
    {'lat': 37.7749, 'lon': -122.4194, 'alt': 10},
    {'lat': 37.7750, 'lon': -122.4180, 'alt': 15},
    {'lat': 37.7755, 'lon': -122.4170, 'alt': 20}
]

upload_mission(waypoints)
start_mission()

Example

This example shows how to program a drone using Python and the dronekit library to follow GPS waypoints. It connects to the drone, defines waypoints, uploads them, and starts the mission.

python

from dronekit import connect, VehicleMode, LocationGlobalRelative, Command
from pymavlink import mavutil
import time

# Connect to the vehicle
vehicle = connect('udp:127.0.0.1:14550', wait_ready=True)

# Define waypoints
waypoints = [
    LocationGlobalRelative(37.7749, -122.4194, 10),
    LocationGlobalRelative(37.7750, -122.4180, 15),
    LocationGlobalRelative(37.7755, -122.4170, 20)
]

# Clear existing missions
cmds = vehicle.commands
cmds.clear()

# Add waypoints to mission
for point in waypoints:
    cmd = Command(0, 0, 0, mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT,
                  mavutil.mavlink.MAV_CMD_NAV_WAYPOINT, 0, 0, 0, 0, 0, 0,
                  point.lat, point.lon, point.alt)
    cmds.add(cmd)
cmds.upload()

# Set mode to AUTO to start mission
vehicle.mode = VehicleMode('AUTO')

# Wait until mission is complete
while True:
    next_wp = vehicle.commands.next
    print(f"Next waypoint: {next_wp}")
    if next_wp == len(waypoints) + 1:
        print("Mission complete")
        break
    time.sleep(1)

# Close vehicle connection
vehicle.close()

Output

Next waypoint: 1
Next waypoint: 2
Next waypoint: 3
Mission complete

Common Pitfalls

• Incorrect coordinate format: GPS points must be in decimal degrees, not degrees-minutes-seconds.
• Not waiting for GPS lock: The drone needs a strong GPS signal before starting the mission.
• Wrong flight mode: The drone must be in AUTO mode or equivalent to follow waypoints.
• Altitude errors: Ensure altitude is relative to takeoff point or sea level as required by your drone.
• Mission upload failure: Always clear previous missions before uploading new ones to avoid conflicts.

python

## Wrong way: Not clearing old missions
cmds = vehicle.commands
# cmds.clear()  # Missing this causes old waypoints to remain

# Right way:
cmds.clear()  # Clear old missions before adding new ones

Quick Reference

Tips for smooth GPS waypoint missions:

• Always verify GPS signal strength before mission start.
• Use decimal degrees for latitude and longitude.
• Clear old missions before uploading new waypoints.
• Set drone to AUTO mode to enable waypoint navigation.
• Monitor mission progress to handle any errors or interruptions.

Key Takeaways

Define GPS waypoints as latitude, longitude, and altitude coordinates in decimal degrees.

Upload the waypoint list to the drone and set its mode to AUTO to start navigation.

Ensure the drone has a strong GPS signal and clear old missions before uploading new ones.

Monitor mission progress to confirm the drone reaches each waypoint successfully.