on MR allow airmode to be sticky and activated by throttle threshold

src/main/fc/fc_core.c

@@ -485,7 +485,7 @@ void processRx(timeUs_t currentTimeUs)
     }
 
     processRcStickPositions(throttleStatus);
-
+    processAirmode();
     updateActivatedModes();
 
 #ifdef USE_PINIOBOX
@@ -589,7 +589,7 @@ void processRx(timeUs_t currentTimeUs)
         /* In MANUAL mode we reset integrators prevent I-term wind-up (PID output is not used in MANUAL) */
         pidResetErrorAccumulators();
     }
-    else {
+    else if (STATE(FIXED_WING) || rcControlsConfig()->airmodeHandlingType == STICK_CENTER) {
         if (throttleStatus == THROTTLE_LOW) {
             if (isAirmodeActive() && !failsafeIsActive() && ARMING_FLAG(ARMED)) {
                 rollPitchStatus_e rollPitchStatus = calculateRollPitchCenterStatus();
@@ -610,6 +610,12 @@ void processRx(timeUs_t currentTimeUs)
         else {
             DISABLE_STATE(ANTI_WINDUP);
         }
+    } else if (rcControlsConfig()->airmodeHandlingType == AIRMODE_THROTTLE_THRESHOLD) {
+        DISABLE_STATE(ANTI_WINDUP);
+        //This case applies only to MR when Airmode management is throttle threshold activated
+        if (throttleStatus == THROTTLE_LOW && !isAirmodeActive()) {
+            pidResetErrorAccumulators();
+        }
     }
 
     if (mixerConfig()->platformType == PLATFORM_AIRPLANE) {

src/main/fc/rc_controls.c

@@ -69,14 +69,15 @@ stickPositions_e rcStickPositions;
 
 FASTRAM int16_t rcCommand[4];           // interval [1000;2000] for THROTTLE and [-500;+500] for ROLL/PITCH/YAW
 
-PG_REGISTER_WITH_RESET_TEMPLATE(rcControlsConfig_t, rcControlsConfig, PG_RC_CONTROLS_CONFIG, 0);
+PG_REGISTER_WITH_RESET_TEMPLATE(rcControlsConfig_t, rcControlsConfig, PG_RC_CONTROLS_CONFIG, 1);
 
 PG_RESET_TEMPLATE(rcControlsConfig_t, rcControlsConfig,
     .deadband = 5,
     .yaw_deadband = 5,
     .pos_hold_deadband = 20,
     .alt_hold_deadband = 50,
-    .deadband3d_throttle = 50
+    .deadband3d_throttle = 50,
+    .airmodeHandlingType = STICK_CENTER
 );
 
 PG_REGISTER_WITH_RESET_TEMPLATE(armingConfig_t, armingConfig, PG_ARMING_CONFIG, 1);

src/main/fc/rc_controls.h

@@ -22,6 +22,8 @@
 #define AUTO_DISARM_DELAY_MIN 0
 #define AUTO_DISARM_DELAY_MAX 60
 
+#define AIRMODE_THROTTLE_THRESHOLD 1250
+
 typedef enum rc_alias {
     ROLL = 0,
     PITCH,
@@ -51,6 +53,11 @@ typedef enum {
     CENTERED
 } rollPitchStatus_e;
 
+typedef enum {
+    STICK_CENTER = 0,
+    THROTTLE_THRESHOLD
+} airmodeAndAntiWindupHandlingType_e;
+
 typedef enum {
     ROL_LO = (1 << (2 * ROLL)),
     ROL_CE = (3 << (2 * ROLL)),
@@ -77,6 +84,7 @@ typedef struct rcControlsConfig_s {
     uint8_t pos_hold_deadband;              // Adds ability to adjust the Hold-position when moving the sticks (assisted mode)
     uint8_t alt_hold_deadband;              // Defines the neutral zone of throttle stick during altitude hold
     uint16_t deadband3d_throttle;           // default throttle deadband from MIDRC
+    uint8_t airmodeHandlingType;            // Defaults to ANTI_WINDUP triggered at sticks centered
 } rcControlsConfig_t;
 
 PG_DECLARE(rcControlsConfig_t, rcControlsConfig);

src/main/fc/rc_modes.c

@@ -31,6 +31,7 @@
 
 #include "fc/config.h"
 #include "fc/rc_controls.h"
+#include "fc/runtime_config.h"
 
 #include "rx/rx.h"
 
@@ -40,6 +41,8 @@ static bool isUsingSticksToArm = true;
 static bool isUsingNAVModes = false;
 #endif
 
+static EXTENDED_FASTRAM uint8_t airmodeActivationFlag = false;
+
 boxBitmask_t rcModeActivationMask; // one bit per mode defined in boxId_e
 
 // TODO(alberto): It looks like we can now safely remove this assert, since everything
@@ -59,9 +62,45 @@ bool isUsingSticksForArming(void)
     return isUsingSticksToArm;
 }
 
+void processAirmode(void) {
+    if (STATE(FIXED_WING) || rcControlsConfig()->airmodeHandlingType == STICK_CENTER) {
+        airmodeActivationFlag = feature(FEATURE_AIRMODE) || IS_RC_MODE_ACTIVE(BOXAIRMODE);
+    } else if (rcControlsConfig()->airmodeHandlingType == THROTTLE_THRESHOLD) {
+
+        if (!ARMING_FLAG(ARMED)) {
+            /*
+             * Disarm disables airmode immediately
+             */
+            airmodeActivationFlag = false;
+        } else if (
+            !airmodeActivationFlag && 
+            rcCommand[THROTTLE] > AIRMODE_THROTTLE_THRESHOLD &&
+            (feature(FEATURE_AIRMODE) || IS_RC_MODE_ACTIVE(BOXAIRMODE))
+        ) {
+            /*
+             * Airmode is allowed to be active only after ARMED and then THROTTLE goes above
+             * activation threshold
+             */
+            airmodeActivationFlag = true;
+        } else if (
+            airmodeActivationFlag &&
+            !feature(FEATURE_AIRMODE) &&
+            !IS_RC_MODE_ACTIVE(BOXAIRMODE)
+        ) {
+            /*
+             *  When user disables BOXAIRMODE, turn airmode off as well
+             */
+            airmodeActivationFlag = false;
+        }
+
+    } else {
+        airmodeActivationFlag = false;
+    }
+}
+
 bool isAirmodeActive(void)
 {
-    return feature(FEATURE_AIRMODE) || IS_RC_MODE_ACTIVE(BOXAIRMODE);
+    return airmodeActivationFlag;
 }
 
 #if defined(USE_NAV)

src/main/fc/rc_modes.h

@@ -121,6 +121,7 @@ void rcModeUpdate(boxBitmask_t *newState);
 bool isModeActivationConditionPresent(boxId_e modeId);
 
 bool isUsingSticksForArming(void);
+void processAirmode(void);
 bool isAirmodeActive(void);
 bool isUsingNavigationModes(void);
 bool isRangeActive(uint8_t auxChannelIndex, const channelRange_t *range);

src/main/fc/settings.yaml

@@ -114,6 +114,8 @@ tables:
     values: ["PT1", "BIQUAD"]
   - name: log_level
     values: ["ERROR", "WARNING", "INFO", "VERBOSE", "DEBUG"]
+  - name: airmodeHandlingType
+    values: ["STICK_CENTER", "THROTTLE_THRESHOLD"]
 
 groups:
   - name: PG_GYRO_CONFIG
@@ -845,6 +847,9 @@ groups:
         field: deadband3d_throttle
         min: 0
         max: 200
+      - name: mc_airmode_type
+        field: airmodeHandlingType
+        table: airmodeHandlingType
 
   - name: PG_PID_PROFILE
     type: pidProfile_t