From 376426a088f752dad3898643039cab592bd81422 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Sat, 16 Sep 2023 09:19:01 +1000
Subject: [PATCH] RC_Channel: added AUX function 112 for AHRS EKF type changes

---
 libraries/RC_Channel/RC_Channel.cpp | 10 ++++++++++
 libraries/RC_Channel/RC_Channel.h   |  1 +
 2 files changed, 11 insertions(+)

diff --git a/libraries/RC_Channel/RC_Channel.cpp b/libraries/RC_Channel/RC_Channel.cpp
index fb85273f26..32023fe9ab 100644
--- a/libraries/RC_Channel/RC_Channel.cpp
+++ b/libraries/RC_Channel/RC_Channel.cpp
@@ -207,6 +207,7 @@ const AP_Param::GroupInfo RC_Channel::var_info[] = {
     // @Values{Plane}: 108:QRTL Mode
     // @Values{Copter}: 109:use Custom Controller
     // @Values{Copter, Rover, Plane, Blimp}:  110:KillIMU3
+    // @Values{Copter,Plane,Rover,Blimp,Sub,Tracker}: 112:SwitchExternalAHRS
     // @Values{Plane}: 150:CRUISE Mode
     // @Values{Copter}: 151:TURTLE Mode
     // @Values{Copter}: 152:SIMPLE heading reset
@@ -700,6 +701,7 @@ void RC_Channel::init_aux_function(const aux_func_t ch_option, const AuxSwitchPo
     case AUX_FUNC::CAMERA_MANUAL_FOCUS:
     case AUX_FUNC::CAMERA_AUTO_FOCUS:
     case AUX_FUNC::CAMERA_LENS:
+    case AUX_FUNC::AHRS_TYPE:
         run_aux_function(ch_option, ch_flag, AuxFuncTriggerSource::INIT);
         break;
     default:
@@ -1613,6 +1615,14 @@ bool RC_Channel::do_aux_function(const aux_func_t ch_option, const AuxSwitchPos
         AP::ahrs().request_yaw_reset();
         break;
 
+    case AUX_FUNC::AHRS_TYPE: {
+#if HAL_NAVEKF3_AVAILABLE && HAL_EXTERNAL_AHRS_ENABLED
+        AP::ahrs().set_ekf_type(ch_flag==AuxSwitchPos::HIGH? 11 : 3);
+#endif
+        break;
+    }
+        
+
 #if HAL_TORQEEDO_ENABLED
     // clear torqeedo error
     case AUX_FUNC::TORQEEDO_CLEAR_ERR: {
diff --git a/libraries/RC_Channel/RC_Channel.h b/libraries/RC_Channel/RC_Channel.h
index bf9d70f5bc..fcf6104773 100644
--- a/libraries/RC_Channel/RC_Channel.h
+++ b/libraries/RC_Channel/RC_Channel.h
@@ -216,6 +216,7 @@ public:
         CUSTOM_CONTROLLER =  109,  // use Custom Controller
         KILL_IMU3 =          110, // disable third IMU (for IMU failure testing)
         LOWEHEISER_STARTER = 111,  // allows for manually running starter
+        AHRS_TYPE =          112, // change AHRS_EKF_TYPE
 
         // if you add something here, make sure to update the documentation of the parameter in RC_Channel.cpp!
         // also, if you add an option >255, you will need to fix duplicate_options_exist