AC_CustomControl: add empty controller backend as a template

libraries/AC_CustomControl/AC_CustomControl.cpp

@@ -6,13 +6,14 @@
 
 
 #include "AC_CustomControl_Backend.h"
+// #include "AC_CustomControl_Empty.h"
 
 // table of user settable parameters
 const AP_Param::GroupInfo AC_CustomControl::var_info[] = {
     // @Param: _TYPE
     // @DisplayName: Custom control type
     // @Description: Custom control type to be used
-    // @Values: 0:None
+    // @Values: 0:None, 1:Empty
     // @RebootRequired: True
     // @User: Advanced
     AP_GROUPINFO_FLAGS("_TYPE", 1, AC_CustomControl, _controller_type, 0, AP_PARAM_FLAG_ENABLE),
@@ -24,6 +25,9 @@ const AP_Param::GroupInfo AC_CustomControl::var_info[] = {
     // @User: Advanced
     AP_GROUPINFO("_AXIS_MASK", 2, AC_CustomControl, _custom_controller_mask, 0),
 
+    // parameters for empty controller. only used as a template, no need for param table 
+    // AP_SUBGROUPVARPTR(_backend, "1_", 6, AC_CustomControl, _backend_var_info[0]),
+
     AP_GROUPEND
 };
 
@@ -44,6 +48,11 @@ void AC_CustomControl::init(void)
     {
         case CustomControlType::CONT_NONE:
             break;
+        case CustomControlType::CONT_EMPTY: // This is template backend. Don't initialize it.
+            // This is template backend. Don't initialize it.
+            // _backend = new AC_CustomControl_Empty(*this, _ahrs, _att_control, _motors, _dt);
+            // _backend_var_info[get_type()] = AC_CustomControl_Empty::var_info;
+            break;
         default:
             return;
     }

libraries/AC_CustomControl/AC_CustomControl.h

@@ -43,6 +43,7 @@ protected:
     // add custom controller here
     enum class CustomControlType : uint8_t {
         CONT_NONE            = 0,
+        CONT_EMPTY           = 1,
     };            // controller that should be used     
 
     enum class  CustomControlOption {

libraries/AC_CustomControl/AC_CustomControl_Empty.cpp

@@ -0,0 +1,72 @@
+#include "AC_CustomControl_Empty.h"
+
+#if CUSTOMCONTROL_EMPTY_ENABLED
+
+#include <GCS_MAVLink/GCS.h>
+
+// table of user settable parameters
+const AP_Param::GroupInfo AC_CustomControl_Empty::var_info[] = {
+    // @Param: PARAM1
+    // @DisplayName: Empty param1
+    // @Description: Dumy parameter for empty custom controller backend
+    // @User: Advanced
+    AP_GROUPINFO("PARAM1", 1, AC_CustomControl_Empty, param1, 0.0f),
+
+    // @Param: PARAM2
+    // @DisplayName: Empty param2
+    // @Description: Dumy parameter for empty custom controller backend
+    // @User: Advanced
+    AP_GROUPINFO("PARAM2", 2, AC_CustomControl_Empty, param2, 0.0f),
+
+    // @Param: PARAM3
+    // @DisplayName: Empty param3
+    // @Description: Dumy parameter for empty custom controller backend
+    // @User: Advanced
+    AP_GROUPINFO("PARAM3", 3, AC_CustomControl_Empty, param3, 0.0f),
+
+    AP_GROUPEND
+};
+
+// initialize in the constructor
+AC_CustomControl_Empty::AC_CustomControl_Empty(AC_CustomControl& frontend, AP_AHRS_View*& ahrs, AC_AttitudeControl_Multi*& att_control, AP_MotorsMulticopter*& motors, float dt) :
+    AC_CustomControl_Backend(frontend, ahrs, att_control, motors, dt)
+{
+    AP_Param::setup_object_defaults(this, var_info);
+}
+
+// update controller
+// return roll, pitch, yaw controller output
+Vector3f AC_CustomControl_Empty::update(void)
+{
+    // reset controller based on spool state
+    switch (_motors->get_spool_state()) {
+        case AP_Motors::SpoolState::SHUT_DOWN:
+        case AP_Motors::SpoolState::GROUND_IDLE:
+            // We are still at the ground. Reset custom controller to avoid
+            // build up, ex: integrator
+            reset();
+            break;
+
+        case AP_Motors::SpoolState::THROTTLE_UNLIMITED:
+        case AP_Motors::SpoolState::SPOOLING_UP:
+        case AP_Motors::SpoolState::SPOOLING_DOWN:
+            // we are off the ground
+            break;
+    }
+
+    // arducopter main attitude controller already runned
+    // we don't need to do anything else
+
+    gcs().send_text(MAV_SEVERITY_INFO, "empty custom controller working");
+
+    // return what arducopter main controller outputted
+    return Vector3f(_motors->get_roll(), _motors->get_pitch(), _motors->get_yaw());
+}
+
+// reset controller to avoid build up on the ground
+// or to provide bumpless transfer from arducopter main controller
+void AC_CustomControl_Empty::reset(void)
+{
+}
+
+#endif

libraries/AC_CustomControl/AC_CustomControl_Empty.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "AC_CustomControl_Backend.h"
+
+#ifndef CUSTOMCONTROL_EMPTY_ENABLED
+    #define CUSTOMCONTROL_EMPTY_ENABLED AP_CUSTOMCONTROL_ENABLED
+#endif
+
+#if CUSTOMCONTROL_EMPTY_ENABLED
+
+class AC_CustomControl_Empty : public AC_CustomControl_Backend {
+public:
+    AC_CustomControl_Empty(AC_CustomControl& frontend, AP_AHRS_View*& ahrs, AC_AttitudeControl_Multi*& att_control, AP_MotorsMulticopter*& motors, float dt);
+
+
+    Vector3f update(void) override;
+    void reset(void) override;
+
+    // user settable parameters
+    static const struct AP_Param::GroupInfo var_info[];
+
+protected:
+    // declare parameters here
+    AP_Float param1;
+    AP_Float param2;
+    AP_Float param3;
+};
+
+#endif