From b917a7143102e133fab89fdd519a5242653992f6 Mon Sep 17 00:00:00 2001
From: Joshua Henderson <hendjoshsr71@gmail.com>
Date: Sun, 2 Jan 2022 02:58:44 -0500
Subject: [PATCH] ArduCopter: add Airspeed support

---
 ArduCopter/AP_Arming.cpp   |  3 +++
 ArduCopter/GCS_Mavlink.cpp | 10 ++++++++++
 ArduCopter/system.cpp      |  4 ++++
 3 files changed, 17 insertions(+)

diff --git a/ArduCopter/AP_Arming.cpp b/ArduCopter/AP_Arming.cpp
index 8430b030ec..415c26d019 100644
--- a/ArduCopter/AP_Arming.cpp
+++ b/ArduCopter/AP_Arming.cpp
@@ -62,6 +62,9 @@ bool AP_Arming_Copter::run_pre_arm_checks(bool display_failure)
         & gcs_failsafe_check(display_failure)
         & winch_checks(display_failure)
         & alt_checks(display_failure)
+#if AP_AIRSPEED_ENABLED
+        & AP_Arming::airspeed_checks(display_failure)
+#endif
         & AP_Arming::pre_arm_checks(display_failure);
 }
 
diff --git a/ArduCopter/GCS_Mavlink.cpp b/ArduCopter/GCS_Mavlink.cpp
index d906dd58bf..e0963d3b72 100644
--- a/ArduCopter/GCS_Mavlink.cpp
+++ b/ArduCopter/GCS_Mavlink.cpp
@@ -195,6 +195,16 @@ void GCS_MAVLINK_Copter::send_nav_controller_output() const
 
 float GCS_MAVLINK_Copter::vfr_hud_airspeed() const
 {
+#if AP_AIRSPEED_ENABLED
+    // airspeed sensors are best. While the AHRS airspeed_estimate
+    // will use an airspeed sensor, that value is constrained by the
+    // ground speed. When reporting we should send the true airspeed
+    // value if possible:
+    if (copter.airspeed.enabled() && copter.airspeed.healthy()) {
+        return copter.airspeed.get_airspeed();
+    }
+#endif
+    
     Vector3f airspeed_vec_bf;
     if (AP::ahrs().airspeed_vector_true(airspeed_vec_bf)) {
         // we are running the EKF3 wind estimation code which can give
diff --git a/ArduCopter/system.cpp b/ArduCopter/system.cpp
index 3d27915028..dd5213b88b 100644
--- a/ArduCopter/system.cpp
+++ b/ArduCopter/system.cpp
@@ -111,6 +111,10 @@ void Copter::init_ardupilot()
     AP::compass().set_log_bit(MASK_LOG_COMPASS);
     AP::compass().init();
 
+#if AP_AIRSPEED_ENABLED
+    airspeed.set_log_bit(MASK_LOG_IMU);
+#endif
+
 #if AC_OAPATHPLANNER_ENABLED == ENABLED
     g2.oa.init();
 #endif