Overview

The FLTMODE parameter group assigns specific autopilot behaviors (Flight Modes) to the physical switch positions on your RC transmitter.

ArduPilot supports up to 6 distinct flight modes accessible via a single RC channel (usually Channel 5). Each position corresponds to a specific PWM range.

Key Concepts

1. Switch Mapping (FLTMODE1...FLTMODE6)

• Position 1 (Low PWM): Controlled by FLTMODE1.
• Position 6 (High PWM): Controlled by FLTMODE6.
• Common Modes:
  • Manual/Stabilize: Pilot has full control.
  • Loiter/PosHold: GPS-based position hold.
  • Auto: Follows a mission.
  • RTL: Returns to home.

2. Mode Channel (FLTMODE_CH)

Defines which RC channel is used for mode selection.

• Default: 5 (Standard).
• Change: Some pilots prefer channel 8 or others.

Parameter Breakdown

• FLTMODE1..6: Integer mode ID (Vehicle dependent).
• FLTMODE_CH: RC channel number.
• FLTMODE_GCSBLOCK: Prevents the Ground Station from changing modes while the RC transmitter is in a specific state.

Integration Guide

1. Configure Transmitter: Use "Mixes" to map a 3-position and 2-position switch to a single channel to achieve 6 positions.
2. Assign Modes: In the GCS "Flight Modes" screen, select your desired modes for each position.
3. Verify: Toggle the switches and ensure the active mode changes in the HUD.

Developer Notes

• Library: AP_Vehicle / libraries/AP_Common.
• IDs: Mode IDs are NOT the same across vehicles (e.g., Copter Mode 0 is Stabilize, but Plane Mode 0 is Manual).