Setting up GPS RescueUpdated 7 months ago

This guide will help you set up GPS Rescue Mode in Betaflight to ensure your drone can return to a designated home position in case of signal loss. This feature is especially useful in long-range flying scenarios. Follow the steps carefully to configure GPS Rescue on your quadcopter.

1. Prerequisites

Before getting started, ensure the following:

• Your quadcopter is equipped with a GPS module compatible with Betaflight (such as BN-180 or BN-220).
• You are running Betaflight version 4.1 or later. Older versions may not have full GPS Rescue functionality.
• If you're using a M10 GPS module it's recommended to upgrade Betaflight to Version 4.5 or newer.

2. Hardware Setup: Installing the GPS Module

• Mount the GPS module on your quadcopter in an open area, away from interference like your VTX (video transmitter) or antennas. It’s usually placed at the rear of the quad to get a clear satellite signal.
• Wire the GPS moduleto your flight controller (FC). Use a UART port (TX and RX pads) on your flight controller.
  • GPS TX → FC RX
  • GPS RX → FC TX
  • Power the GPS by connecting it to a 5V and GND pad.
• Double-check the wiring connections before moving on to configuration.

3. Configuring the UART Port for GPS in Betaflight

1. Connect your flight controller to your computer and open Betaflight Configurator.
2. Navigate to the Ports tab.
3. Find the UART port where you connected the GPS module.
   • In the “Peripherals” column of that UART, select GPS from the dropdown menu.
4. Click Save and Reboot to apply the changes.

4. Configuring GPS Settings in Betaflight

1. Once the FC has rebooted, go to the Configuration tab.
2. Scroll down to the GPS section.
3. Toggle ON the GPS option.
4. Set the correct GPS protocol:
   • Most GPS modules use the UBLOX protocol, so select this unless your GPS specifies something different.
5. If your GPS module includes a magnetometer (compass), enable it by toggling Magnetometer (optional).
6. Click Save and Reboot.

5. Calibrating and Testing the GPS

1. Wait for GPS lock:
   • It may take a few minutes for your GPS module to get its first lock on satellites (especially in a new location).
   • You’ll need a minimum of 6 satellites to fly safely. For better accuracy and performance, aim for more than 8 satellites.
2. Go to the Betaflight OSD or use the GPS tab in the configurator to check the number of satellites, GPS coordinates, and other information. Ensure everything is functioning correctly before proceeding.

6. Setting Up GPS Rescue Mode in Failsafe

1. In Betaflight Configurator, go to the Failsafe tab.
2. Under Stage 2 Failsafe Procedure, select GPS Rescuefrom the dropdown menu.
   • This means that when your drone loses connection with the transmitter, GPS Rescue will automatically trigger and return the quad to the home position (where it last acquired a GPS lock before takeoff).
3. Fine-tune GPS Rescue parameters:
   • Minimum Satellites for Fix: Set this to at least 6 to ensure GPS Rescue only activates when there’s a solid GPS lock.
   • Initial Climb Height: Set this to around 100m (or higher) to ensure the quad climbs to a safe altitude before heading home.
   • Descent Speed: Set this to a reasonable value (e.g., 50 cm/s) for a controlled descent.
   • Max Home Distance: This limits the maximum distance for GPS Rescue to engage. If your quad is beyond this distance, Rescue won’t activate.
4. Click Save and Reboot.

7. Optional: Assigning a Manual GPS Rescue Switch

You can manually activate GPS Rescue Mode by assigning it to a switch on your transmitter.

1. Go to the Modes tab in Betaflight Configurator.
2. Look for GPS Rescue and assign it to an AUX channel that corresponds to a switch on your transmitter.
3. Adjust the range so that when you flip the switch, the GPS Rescue Mode is triggered.
4. Click Save.

8. Testing GPS Rescue Mode

Before flying with GPS Rescue, it is crucial to test it in a controlled environment.

1. Check home position: Before arming your quad, ensure that you have a proper GPS lock and that the home position (where the quad took off) is recorded. You can monitor this in the Betaflight OSD or via the Configurator.

2. Test GPS Rescue in manual mode:

   • Fly your quad in a safe, open area with a good GPS signal.
   • At a safe altitude, activate the GPS Rescue switch (if set up) or simulate failsafe conditions (e.g., by turning off your transmitter momentarily).
   • Watch to see if the quad gains altitude, turns towards the home point, and begins to return.

3. Check the failsafe behavior:

   • After GPS Rescue is triggered, verify that your quadcopter climbs to the specified altitude, returns to the home position, and begins descending.
   • Once the quad gets close to the home point, you can regain control by reactivating your transmitter or disarming the quad manually.

4. Testing failsafe:

   • Set up a soft failsafe to see if the GPS Rescue activates when the transmitter loses signal.

9. Troubleshooting Tips

• Not getting GPS lock? Check the wiring of your GPS module and make sure it's placed away from interference. Re-check if the correct protocol (UBLOX) is selected in Betaflight.
• GPS Rescue not climbing high enough? Double-check the settings in the Failsafe tab, especially the Initial Climb Height.
• GPS Rescue drifting? Ensure that you have a solid GPS lock before takeoff (at least 6 satellites). More satellites will provide more accurate positioning.
• Quad doesn’t return to home point? Check the Home Distance setting and make sure that the home point is being set correctly before arming.

Final Notes

• Always test GPS Rescue Mode in a controlled environment before relying on it in critical situations.
• GPS Rescue is not foolproof and can be affected by the environment, poor GPS signal, or incorrect configuration. Use it as a last resort for failsafe, and always fly responsibly.