Betaflight 4.5 GPS Rescue Setup and Testing

Introduction

• Betaflight 4.5 brings numerous bug fixes and feature improvements.
• Focus of this lecture: Fixes and improvements in the GPS Rescue (Return to Home) function.
• Historically, GPS Rescue in Betaflight was unreliable, but has seen improvements.
• Proper configuration is essential to avoid issues.

Initial Steps

• Connecting GPS to Flight Controller
  • Connect the GPS to the flight controller using TX to RX and RX to TX.
  • For compasses, connect SDA and SCL (if available).
  • Power GPS using 5V or 3.3V pad, preferably from a USB-power pad for quicker satellite lock.

Betaflight Configurator Setup

1. Port Setup

   • Go to the Ports tab and set the GPS on the corresponding UART port.

2. GPS Tab

   • Choose settings: U-blox, Auto baud, Auto configure.
   • Confirm functionality through the GPS icon (yellow/red) in the configurator.

3. Optional Configurations

   • Use Galileo: Improves positioning accuracy.
   • Ground Assistance Type: Additionally helps with positioning.
   • Set Home Point Once: Determines whether to set home point only on the first arm or every re-arm.

Calibration and Testing

1. Auto-Level Check

   • Ensure the accelerometer is calibrated.
   • Hover in angle mode to confirm minimal drift.

2. Determine Hover Throttle

   • Hover the quad and note the throttle percentage for hover.

Configuring Failsafe Throttle

• Stage 1 Failsafe
  • Set failsafe throttle to hover value during stage 1 to prevent crashing before GPS Rescue kicks in.
• GPS Rescue Throttle
  • Set a slightly higher throttle value for GPS rescue to ensure slight climb.

Configuring Baud Rate

• Recommended: 57600 for most consistent performance.
• Adjust using Betaflight configurator if needed.

Testing GPS Rescue

1. Manual Mode Activation

   • Setup GPS Rescue mode and test it in a safe environment.
   • Check the direction home arrow when flying straight to confirm it points correctly.

2. Failsafe Configurations

   • Use the fail-safe switch in modes tab and configure it to act like GPS rescue.
   • Test to ensure failsafe leads to an auto-landing.

Final Setup

1. Setting GPS Rescue for True Failsafe
   • In the failsafe tab, set the default behavior to GPS Rescue.
   • Ensure proper settings for altitude and throttle behavior during GPS Rescue.
   • Add OSD setting for hdop to monitor GPS lock health.

Final Notes

• Main Takeaways
  • Regular test flights of GPS rescue.
  • Make sure HDOP value is low, significant number of satellites locked before flight.
  • Ensure proper home direction checks after take-off for reliability.

Supporting the Creator

• Reminder to support Joshua Bardwell via Patreon for more valuable content.

References

• Additional Betaflight 4.5 new features and bug fixes.
• Mentioned tutorial and supporting link provided in the video description.