Ardupilot Auxiliary Function Switches Reference Guide
A comprehensive technical index of Ardupilot auxiliary function switch IDs, flight modes, automated triggers, and safety interlocks for advanced UAV and multi-rotor configurations.
1. Overview of Ardupilot Auxiliary Functions
Ardupilot allows pilots and engineers to map auxiliary switches (CH6 through CH16) to a wide variety of software actions, flight modes, safety triggers, and payload operations. This reference breaks down every major function index, explaining its operational behavior and system purpose.
Configuration Tip: Ensure your transmitter mixes and servo endpoints are properly scaled (-100% to +100%, or 1000µs to 2000µs) so that multi-position switches cleanly trigger low, mid, and high range thresholds in Mission Planner or QGroundControl.
2. Master Auxiliary Function Index
| ID | Function Name | Detailed Operational Description |
|---|---|---|
| 0 | Do Nothing | Unassigned or inactive auxiliary channel slot. |
| 2 | FLIP Mode | Initiates automatic acrobatic flip routine (multirotor specific). |
| 3 | Simple Mode | Locks control orientation relative to the pilot's takeoff position regardless of craft heading. |
| 4 | RTL | Triggers Return-to-Launch mode, flying the vehicle back to its home coordinate. |
| 5 | Save Trim | Saves current RC trim offsets to flight controller EEPROM. |
| 7 | Save WP | Stores current vehicle location as a temporary waypoint in mission memory. |
| 9 | Camera Trigger | Manually triggers an onboard camera shutter via servo or relay output. |
| 10 | RangeFinder Enable | Enables or disables active downward rangefinder (lidar/sonar) altitude input. |
| 11 | Fence Enable | Activates the geofence boundary to restrict vehicle flight area. |
| 13 | Super Simple Mode | Flight orientation mode referenced to home where pulling back always flies the craft toward home. |
| 14 | Acro Trainer | Limits maximum roll and pitch angles while operating in Acro flight mode. |
| 15 | Sprayer Enable | Activates agricultural liquid spray pump systems. |
| 16 | AUTO Mode | Switches flight mode to autonomous mission waypoint execution. |
| 17 | AUTOTUNE Mode | Initiates automated PID tuning routine for multirotors. |
| 18 | LAND Mode | Commands the vehicle to descend and land straight down at its current location. |
| 19 | Gripper Release | Opens or releases a mechanical cargo gripper payload mechanism. |
| 21 | Parachute Enable | Arms the emergency recovery parachute deployment system. |
| 22 | Parachute Release | Manually deploys the emergency recovery parachute instantly. |
| 23 | Parachute 3pos | Three-position switch control for Parachute (Off, Armed, Released). |
| 24 | Auto Mission Reset | Resets the active automated mission sequence back to waypoint 1. |
| 25 | AttCon Feed Forward | Toggles attitude controller feed-forward response tuning. |
| 26 | AttCon Accel Limits | Enables or adjusts attitude controller acceleration limits. |
| 27 | Retract Mount1 | Retracts camera gimbal mount 1 into protective housing. |
| 28 | Relay1 On/Off | Toggles onboard electrical relay 1 state. |
| 29 | Landing Gear | Controls retractable physical landing gear servos or solenoids. |
| 30 | Lost Copter Sound | Triggers audible buzzer/beeper to help locate a downed aircraft. |
| 31 | Motor Emergency Stop | Cuts all motor outputs instantly regardless of flight state (critical safety switch). |
| 32 | Motor Interlock | Safety enable switch; motors will not spool up unless interlock is engaged. |
| 33 | BRAKE Mode | Commands multirotors to halt immediately and hold position. |
| 34 | Relay2 On/Off | Toggles onboard electrical relay 2 state. |
| 35 | Relay3 On/Off | Toggles onboard electrical relay 3 state. |
| 36 | Relay4 On/Off | Toggles onboard electrical relay 4 state. |
| 37 | THROW Mode | Enables throw-to-start launch mode for multirotors. |
| 38 | ADSB Avoidance Enable | Enables transponder-based ADSB traffic collision avoidance. |
| 39 | PrecLoiter Enable | Engages precision loiter landing over an IR/optical precision landing beacon. |
| 40 | Proximity Avoidance Enable | Enables obstacle detection avoidance using LiDAR or radar sensors. |
| 41 | ArmDisarm (4.1 and lower) | Legacy manual arming and disarming switch function for older firmware. |
| 42 | SMARTRTL Mode | Engages Smart Return-to-Launch, retracing the safe recorded path home. |
| 43 | InvertedFlight Enable | Enables inverted flight stabilization parameters (supported airframes). |
| 44 | Winch Enable | Powers and enables cargo winch deployment systems. |
| 45 | Winch Control | Manual spool control for active cargo winches. |
| 46 | RC Override Enable | Allows ground station or companion computer overrides to be toggled via RC. |
| 47 | User Function 1 | Custom user-scriptable auxiliary trigger slot 1. |
| 48 | User Function 2 | Custom user-scriptable auxiliary trigger slot 2. |
| 49 | User Function 3 | Custom user-scriptable auxiliary trigger slot 3. |
| 52 | ACRO Mode | Switches flight mode to Rate-based Acrobatic flight. |
| 55 | GUIDED Mode | Switches flight mode to external GCS or companion computer guided navigation. |
| 56 | LOITER Mode | Switches flight mode to GPS-stabilized position and altitude hold. |
| 57 | FOLLOW Mode | Engages target tracking mode (following a moving Mavlink beacon/GPS). |
| 58 | Clear Waypoints | Clears stored mission waypoint buffer from memory. |
| 60 | ZigZag Mode | Engages agricultural or inspection ZigZag grid flight pattern. |
| 61 | ZigZag SaveWP | Saves start/end waypoints for ZigZag operational grids. |
| 62 | Compass Learn | Enables inflight automatic compass offset learning. |
| 65 | GPS Disable | Temporarily disables GPS sensor input (useful for troubleshooting magnetic interference). |
| 66 | Relay5 On/Off | Toggles onboard electrical relay 5 state. |
| 67 | Relay6 On/Off | Toggles onboard electrical relay 6 state. |
| 68 | STABILIZE Mode | Switches flight mode to self-leveling attitude stabilization. |
| 69 | POSHOLD Mode | Engages Position Hold combining optical flow/GPS and manual stick damping. |
| 70 | ALTHOLD Mode | Engages Altitude Hold while allowing manual roll/pitch control. |
| 71 | FLOWHOLD Mode | Engages optical-flow assisted position hold without GPS reliance. |
| 72 | CIRCLE Mode | Commands vehicle to orbit a designated center point at a set radius. |
| 73 | DRIFT Mode | Simulates flying an RC airplane feel while maintaining GPS coordinate safety. |
| 75 | SurfaceTrackingUpDown | Adjusts target offset height during terrain-following operations. |
| 76 | STANDBY Mode | Places vehicle into low-power idle standby state. |
| 78 | RunCam Control | Triggers RunCam HD camera recording and mode changes. |
| 79 | RunCam OSD Control | Toggles RunCam on-screen display menu navigation. |
| 80 | VisOdom Align | Aligns visual odometry coordinate frames with external sensors. |
| 81 | Disarm | Dedicated instant disarm switch command. |
| 83 | ZigZag Auto | Executes automated agricultural grid sweeps. |
| 84 | AirMode | Toggles AirMode, maintaining PID attitude control authority at zero throttle. |
| 85 | Generator | Controls internal combustion generator starting/choke systems. |
| 90 | EKF Source Set | Switches active EKF navigation sensor source weightings. |
| 94 | VTX Power | Adjusts video transmitter broadcast output power levels. |
| 99 | AUTO RTL | Initiates automated safety return-to-launch routine. |
| 100 | KillIMU1 | Simulates IMU 1 sensor failure for sensor redundancy testing. |
| 101 | KillIMU2 | Simulates IMU 2 sensor failure for sensor redundancy testing. |
| 102 | Camera Mode Toggle | Cycles between camera photo, video, and mapping modes. |
| 105 | GPS Disable Yaw | Disables GPS-based yaw alignment assistance. |
| 109 | use Custom Controller | Engages user-defined custom control loops. |
| 110 | KillIMU3 | Simulates IMU 3 sensor failure for sensor redundancy testing. |
| 112 | SwitchExternalAHRS | Toggles between primary AHRS and external backup navigation attitude sensors. |
| 113 | Retract Mount2 | Retracts secondary camera gimbal mount 2. |
| 151 | TURTLE Mode | Engages flip-over-after-crash (reverse motor direction) recovery mode. |
| 152 | SIMPLE heading reset | Resets the Simple Mode magnetic heading reference direction. |
| 153 | ArmDisarm (4.2 and higher) | Standardized manual arm/disarm switch for Ardupilot 4.2+. |
| 154 | ArmDisarm with AirMode (4.2 and higher) | Arms vehicle and simultaneously engages AirMode stabilization. |
| 158 | Optflow Calibration | Initiates optical flow sensor scale calibration routine. |
| 159 | Force IS_Flying | Forces flight controller state machine into flight mode. |
| 161 | Turbine Start (heli) | Initiates automated turbine engine start sequence for heli/jet setups. |
| 162 | FFT Tune | Triggers dynamic in-flight Fast Fourier Transform filter frequency analysis. |
| 163 | Mount Lock | Locks camera gimbal position relative to earth/horizon frame. |
| 164 | Pause Stream Logging | Temporarily pauses onboard Dataflash debug log writing. |
| 165 | Arm/Emergency Motor Stop | Dual-function switch for normal arming and instant emergency cut. |
| 166 | Camera Record Video | Starts or stops onboard video recording. |
| 167 | Camera Zoom | Controls optical/digital camera lens zoom steps. |
| 168 | Camera Manual Focus | Adjusts camera lens focus manually. |
| 169 | Camera Auto Focus | Triggers automated camera contrast/phase autofocus sweep. |
| 171 | Calibrate Compasses | Initiates onboard compass calibration sequence. |
| 172 | Battery MPPT Enable | Enables solar Maximum Power Point Tracking charging regulators. |
| 174 | Camera Image Tracking | Engages computer vision target tracking on supported companion payloads. |
| 175 | Camera Lens | Switches between multiple optical camera lenses. |
| 177 | Mount LRF enable | Enables Laser Range Finder integrated into camera gimbal. |
| 178 | FlightMode Pause/Resume | Pauses waypoint execution in Auto mode and holds position. |
| 180 | Test autotuned gains | Applies and tests newly calculated autotune PID gains in flight. |
| 212 | Mount1 Roll | Manual auxiliary control of Gimbal Mount 1 Roll axis. |
| 213 | Mount1 Pitch | Manual auxiliary control of Gimbal Mount 1 Pitch axis. |
| 214 | Mount1 Yaw | Manual auxiliary control of Gimbal Mount 1 Yaw axis. |
| 215 | Mount2 Roll | Manual auxiliary control of Gimbal Mount 2 Roll axis. |
| 216 | Mount2 Pitch | Manual auxiliary control of Gimbal Mount 2 Pitch axis. |
| 217 | Mount2 Yaw | Manual auxiliary control of Gimbal Mount 2 Yaw axis. |
| 219 | Transmitter Tuning | Assigns auxiliary knob/slider to dynamically tune active PID or filter variables. |
| 300 | Scripting1 | Triggers Lua script event handler 1. |
| 301 | Scripting2 | Triggers Lua script event handler 2. |
| 302 | Scripting3 | Triggers Lua script event handler 3. |
| 303 | Scripting4 | Triggers Lua script event handler 4. |
| 304 | Scripting5 | Triggers Lua script event handler 5. |
| 305 | Scripting6 | Triggers Lua script event handler 6. |
| 306 | Scripting7 | Triggers Lua script event handler 7. |
| 307 | Scripting8 | Triggers Lua script event handler 8. |