RC_Channel: add RC_OPTIONS bit to clear RC override by RC input change

libraries/RC_Channel/RC_Channel.cpp

@@ -290,10 +290,12 @@ bool RC_Channel::get_reverse(void) const
 // read input from hal.rcin or overrides
 bool RC_Channel::update(void)
 {
+    raw_radio_in = hal.rcin->read(ch_in);
+
     if (has_override() && !rc().option_is_enabled(RC_Channels::Option::IGNORE_OVERRIDES)) {
         radio_in = override_value;
     } else if (rc().has_had_rc_receiver() && !rc().option_is_enabled(RC_Channels::Option::IGNORE_RECEIVER)) {
-        radio_in = hal.rcin->read(ch_in);
+        radio_in = raw_radio_in;
     } else {
         return false;
     }
@@ -479,6 +481,13 @@ bool RC_Channel::in_trim_dz() const
     return is_bounded_int32(radio_in, radio_trim - dead_zone, radio_trim + dead_zone);
 }
 
+/*
+  return true if raw input is within deadzone of trim
+*/
+bool RC_Channel::in_raw_trim_dz() const
+{
+    return is_bounded_int32(raw_radio_in, radio_trim - dead_zone, radio_trim + dead_zone);
+}
 
 /*
    return trues if input is within deadzone of min
@@ -494,6 +503,11 @@ void RC_Channel::set_override(const uint16_t v, const uint32_t timestamp_ms)
         return;
     }
 
+    // set the throttle value when the override is first activated
+    if (override_value == 0 && ch_in == rc().get_throttle_channel().ch_in) {
+        rc().override_start_throttle = raw_radio_in;
+    }
+
     last_override_time = timestamp_ms != 0 ? timestamp_ms : AP_HAL::millis();
     override_value = v;
     rc().new_override_received();

libraries/RC_Channel/RC_Channel.h

@@ -65,6 +65,8 @@ class RC_Channel {
 
     // return true if input is within deadzone of trim
     bool       in_trim_dz() const;
+    // return true if raw input is within deadzone of trim
+    bool       in_raw_trim_dz() const;
 
     int16_t    get_radio_in() const { return radio_in;}
     void       set_radio_in(int16_t val) {radio_in = val;}
@@ -378,6 +380,7 @@ class RC_Channel {
 
     // pwm is stored here
     int16_t     radio_in;
+    int16_t     raw_radio_in;
 
     // value generated from PWM normalised to configured scale
     int16_t    control_in;
@@ -496,6 +499,9 @@ class RC_Channels {
     // is RC channel 1.  Beware this is not a cheap call.
     uint16_t get_override_mask() const;
 
+    // determine if the current RC overrides should be cleared due to pilot input
+    bool should_clear_overrides(void);
+
     class RC_Channel *find_channel_for_option(const RC_Channel::AUX_FUNC option);
     bool duplicate_options_exist();
     RC_Channel::AuxSwitchPos get_channel_pos(const uint8_t rcmapchan) const;
@@ -536,6 +542,7 @@ class RC_Channels {
         USE_CRSF_LQ_AS_RSSI     = (1U << 11), // returns CRSF link quality as RSSI value, instead of RSSI
         CRSF_FM_DISARM_STAR     = (1U << 12), // when disarmed, add a star at the end of the flight mode in CRSF telemetry
         ELRS_420KBAUD           = (1U << 13), // use 420kbaud for ELRS protocol
+        CLEAR_OVERRIDES_BY_RC   = (1U << 14), // clear MAVLink overrides if the pilot inputs any of roll/pitch/throttle/yaw
     };
 
     bool option_is_enabled(Option option) const {
@@ -634,6 +641,7 @@ class RC_Channels {
     bool has_new_overrides;
     bool _has_had_rc_receiver; // true if we have had a direct detach RC receiver, does not include overrides
     bool _has_had_override; // true if we have had an override on any channel
+    int16_t override_start_throttle; // throttle value when override was activated
 
     AP_Float _override_timeout;
     AP_Int32  _options;

libraries/RC_Channel/RC_Channels.cpp

@@ -31,6 +31,7 @@ extern const AP_HAL::HAL& hal;
 #include <AP_Math/AP_Math.h>
 #include <AP_Logger/AP_Logger.h>
 #include <AP_RCMapper/AP_RCMapper.h>
+#include <GCS_MAVLink/GCS.h>
 
 #include "RC_Channel.h"
 
@@ -90,9 +91,37 @@ bool RC_Channels::read_input(void)
         success |= channel(i)->update();
     }
 
+    // check if clear overrides by RC is allowed by RC_OPTIONS and any change in RC input during RC overrides
+    if (should_clear_overrides()) {
+        // clear RC overrides
+        set_gcs_overrides_enabled(false);
+        GCS_SEND_TEXT(MAV_SEVERITY_NOTICE, "RC overrides cleared by pilot input");
+    }
+
     return success;
 }
 
+bool RC_Channels::should_clear_overrides(void)
+{
+    if (!rc().option_is_enabled(Option::CLEAR_OVERRIDES_BY_RC) || !has_active_overrides()) {
+        return false;
+    }
+
+    // check for pilot input exceeding the deadzone on roll, pitch, or yaw
+    if (!get_roll_channel().in_raw_trim_dz() ||
+        !get_pitch_channel().in_raw_trim_dz() ||
+        !get_yaw_channel().in_raw_trim_dz()) {
+        return true;
+    }
+
+    // check if the throttle input has changed beyond the deadzone since the override started
+    if (abs(get_throttle_channel().raw_radio_in - override_start_throttle) > get_throttle_channel().get_dead_zone()) {
+        return true;
+    }
+
+    return false;
+}
+
 uint8_t RC_Channels::get_valid_channel_count(void)
 {
     return MIN(NUM_RC_CHANNELS, hal.rcin->num_channels());