From 09a9bd73a4e0e8bc42a369de8070ed10b2acf2df Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Fri, 5 Feb 2021 13:28:08 +1100
Subject: [PATCH] ArduCopter: move handling of last-seen-SYSID_MYGCS up to GCS
 base class

---
 ArduCopter/Copter.h        |  1 -
 ArduCopter/GCS_Mavlink.cpp | 20 +++-----------------
 ArduCopter/GCS_Mavlink.h   |  1 -
 ArduCopter/events.cpp      |  9 +++++++--
 ArduCopter/failsafe.cpp    |  2 +-
 5 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/ArduCopter/Copter.h b/ArduCopter/Copter.h
index 5e8c80cceb..172f82d8c7 100644
--- a/ArduCopter/Copter.h
+++ b/ArduCopter/Copter.h
@@ -386,7 +386,6 @@ private:
 
     // Failsafe
     struct {
-        uint32_t last_heartbeat_ms;      // the time when the last HEARTBEAT message arrived from a GCS - used for triggering gcs failsafe
         uint32_t terrain_first_failure_ms;  // the first time terrain data access failed - used to calculate the duration of the failure
         uint32_t terrain_last_failure_ms;   // the most recent time terrain data access failed
 
diff --git a/ArduCopter/GCS_Mavlink.cpp b/ArduCopter/GCS_Mavlink.cpp
index 51d1ab460e..4daa0e6b2c 100644
--- a/ArduCopter/GCS_Mavlink.cpp
+++ b/ArduCopter/GCS_Mavlink.cpp
@@ -562,13 +562,6 @@ void GCS_MAVLINK_Copter::send_banner()
                                                  copter.motors->get_type_string());
 }
 
-// a RC override message is considered to be a 'heartbeat' from the ground station for failsafe purposes
-void GCS_MAVLINK_Copter::handle_rc_channels_override(const mavlink_message_t &msg)
-{
-    copter.failsafe.last_heartbeat_ms = AP_HAL::millis();
-    GCS_MAVLINK::handle_rc_channels_override(msg);
-}
-
 void GCS_MAVLINK_Copter::handle_command_ack(const mavlink_message_t &msg)
 {
     copter.command_ack_counter++;
@@ -999,14 +992,6 @@ void GCS_MAVLINK_Copter::handleMessage(const mavlink_message_t &msg)
 
     switch (msg.msgid) {
 
-    case MAVLINK_MSG_ID_HEARTBEAT:      // MAV ID: 0
-    {
-        // We keep track of the last time we received a heartbeat from our GCS for failsafe purposes
-        if (msg.sysid != copter.g.sysid_my_gcs) break;
-        copter.failsafe.last_heartbeat_ms = AP_HAL::millis();
-        break;
-    }
-
     case MAVLINK_MSG_ID_MANUAL_CONTROL:
     {
         if (msg.sysid != copter.g.sysid_my_gcs) {
@@ -1031,8 +1016,9 @@ void GCS_MAVLINK_Copter::handleMessage(const mavlink_message_t &msg)
         manual_override(copter.channel_throttle, packet.z, 0, 1000, tnow);
         manual_override(copter.channel_yaw, packet.r, 1000, 2000, tnow);
 
-        // a manual control message is considered to be a 'heartbeat' from the ground station for failsafe purposes
-        copter.failsafe.last_heartbeat_ms = tnow;
+        // a manual control message is considered to be a 'heartbeat'
+        // from the ground station for failsafe purposes
+        gcs().sysid_myggcs_seen(tnow);
         break;
     }
 
diff --git a/ArduCopter/GCS_Mavlink.h b/ArduCopter/GCS_Mavlink.h
index 2c8a381c81..e404b0ddf1 100644
--- a/ArduCopter/GCS_Mavlink.h
+++ b/ArduCopter/GCS_Mavlink.h
@@ -49,7 +49,6 @@ private:
     void handle_command_ack(const mavlink_message_t &msg) override;
     bool handle_guided_request(AP_Mission::Mission_Command &cmd) override;
     void handle_change_alt_request(AP_Mission::Mission_Command &cmd) override;
-    void handle_rc_channels_override(const mavlink_message_t &msg) override;
     bool try_send_message(enum ap_message id) override;
 
     void packetReceived(const mavlink_status_t &status,
diff --git a/ArduCopter/events.cpp b/ArduCopter/events.cpp
index 13ad80d95a..f5a97ddb86 100644
--- a/ArduCopter/events.cpp
+++ b/ArduCopter/events.cpp
@@ -112,13 +112,18 @@ void Copter::handle_battery_failsafe(const char *type_str, const int8_t action)
 void Copter::failsafe_gcs_check()
 {
     // Bypass GCS failsafe checks if disabled or GCS never connected
-    if (g.failsafe_gcs == FS_GCS_DISABLED || failsafe.last_heartbeat_ms == 0) {
+    if (g.failsafe_gcs == FS_GCS_DISABLED) {
+        return;
+    }
+
+    const uint32_t gcs_last_seen_ms = gcs().sysid_myggcs_last_seen_time_ms();
+    if (gcs_last_seen_ms == 0) {
         return;
     }
 
     // calc time since last gcs update
     // note: this only looks at the heartbeat from the device id set by g.sysid_my_gcs
-    const uint32_t last_gcs_update_ms = millis() - failsafe.last_heartbeat_ms;
+    const uint32_t last_gcs_update_ms = millis() - gcs_last_seen_ms;
     const uint32_t gcs_timeout_ms = uint32_t(constrain_float(g2.fs_gcs_timeout * 1000.0f, 0.0f, UINT32_MAX));
 
     // Determine which event to trigger
diff --git a/ArduCopter/failsafe.cpp b/ArduCopter/failsafe.cpp
index c3ee045c88..75e44f36ec 100644
--- a/ArduCopter/failsafe.cpp
+++ b/ArduCopter/failsafe.cpp
@@ -84,6 +84,6 @@ void Copter::afs_fs_check(void)
 #else
     const bool fence_breached = false;
 #endif
-    g2.afs.check(failsafe.last_heartbeat_ms, fence_breached, last_radio_update_ms);
+    g2.afs.check(fence_breached, last_radio_update_ms);
 }
 #endif