From 07d9e8c2246f1e63cbdae5daf4683d60c2666b5f Mon Sep 17 00:00:00 2001
From: bnsgeyer <bnsgeyer@aol.com>
Date: Sat, 26 Jan 2019 09:33:32 -0500
Subject: [PATCH] Copter: Tradheli-removed hard coding of motor interlock to
 channel 8

---
 ArduCopter/AP_Arming.cpp |  8 ++++++++
 ArduCopter/heli.cpp      | 16 +++++++---------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/ArduCopter/AP_Arming.cpp b/ArduCopter/AP_Arming.cpp
index ac672a8a7f..e95ee0d847 100644
--- a/ArduCopter/AP_Arming.cpp
+++ b/ArduCopter/AP_Arming.cpp
@@ -211,6 +211,14 @@ bool AP_Arming_Copter::parameter_checks(bool display_failure)
             }
             return false;
         }
+        // Ensure an Aux Channel is configured for motor interlock
+        if (rc().find_channel_for_option(RC_Channel::aux_func_t::MOTOR_INTERLOCK) == nullptr) {
+            if (display_failure) {
+                gcs().send_text(MAV_SEVERITY_CRITICAL,"PreArm: Motor Interlock not configured");
+            }
+            return false;
+        }
+
         #endif // HELI_FRAME
 
         // check for missing terrain data
diff --git a/ArduCopter/heli.cpp b/ArduCopter/heli.cpp
index 2bf3358ea7..2db03c816f 100644
--- a/ArduCopter/heli.cpp
+++ b/ArduCopter/heli.cpp
@@ -139,17 +139,17 @@ void Copter::heli_update_rotor_speed_targets()
 
     // get rotor control method
     uint8_t rsc_control_mode = motors->get_rsc_mode();
-
-    float rsc_control_deglitched = rotor_speed_deglitch_filter.apply((float)RC_Channels::rc_channel(CH_8)->get_control_in()) * 0.001f;
-
+    float rsc_control_deglitched = 0.0f;
+    RC_Channel *rc_ptr = rc().find_channel_for_option(RC_Channel::aux_func::MOTOR_INTERLOCK);
+    if (rc_ptr != nullptr) {
+        rsc_control_deglitched = rotor_speed_deglitch_filter.apply((float)rc_ptr->get_control_in()) * 0.001f;
+    }
     switch (rsc_control_mode) {
         case ROTOR_CONTROL_MODE_SPEED_PASSTHROUGH:
             // pass through pilot desired rotor speed if control input is higher than 10, creating a deadband at the bottom
-            if (rsc_control_deglitched > 0.01f) {
-                ap.motor_interlock_switch = true;
+            if (motors->get_interlock()) {
                 motors->set_desired_rotor_speed(rsc_control_deglitched);
             } else {
-                ap.motor_interlock_switch = false;
                 motors->set_desired_rotor_speed(0.0f);
             }
             break;
@@ -158,11 +158,9 @@ void Copter::heli_update_rotor_speed_targets()
         case ROTOR_CONTROL_MODE_CLOSED_LOOP_POWER_OUTPUT:
             // pass setpoint through as desired rotor speed, this is almost pointless as the Setpoint serves no function in this mode
             // other than being used to create a crude estimate of rotor speed
-            if (rsc_control_deglitched > 0.0f) {
-                ap.motor_interlock_switch = true;
+            if (motors->get_interlock()) {
                 motors->set_desired_rotor_speed(motors->get_rsc_setpoint());
             }else{
-                ap.motor_interlock_switch = false;
                 motors->set_desired_rotor_speed(0.0f);
             }
             break;