Copter: option to force arm, bypassing checks

ArduCopter/Copter.h

@@ -834,7 +834,7 @@ private:
     // motors.cpp
     void arm_motors_check();
     void auto_disarm_check();
-    bool init_arm_motors(bool arming_from_gcs);
+    bool init_arm_motors(bool arming_from_gcs, bool do_arming_checks=true);
     void init_disarm_motors();
     void motors_output();
     void lost_vehicle_check();

ArduCopter/GCS_Mavlink.cpp

@@ -961,7 +961,8 @@ void GCS_MAVLINK_Copter::handleMessage(mavlink_message_t* msg)
         case MAV_CMD_COMPONENT_ARM_DISARM:
             if (is_equal(packet.param1,1.0f)) {
                 // attempt to arm and return success or failure
-                if (copter.init_arm_motors(true)) {
+                const bool do_arming_checks = !is_equal(packet.param2,2989.0f);
+                if (copter.init_arm_motors(true, do_arming_checks)) {
                     result = MAV_RESULT_ACCEPTED;
                 }
             } else if (is_zero(packet.param1))  {

ArduCopter/motors.cpp

@@ -127,7 +127,7 @@ void Copter::auto_disarm_check()
 
 // init_arm_motors - performs arming process including initialisation of barometer and gyros
 //  returns false if arming failed because of pre-arm checks, arming checks or a gyro calibration failure
-bool Copter::init_arm_motors(bool arming_from_gcs)
+bool Copter::init_arm_motors(const bool arming_from_gcs, const bool do_arming_checks)
 {
     static bool in_arm_motors = false;
 
@@ -144,7 +144,7 @@ bool Copter::init_arm_motors(bool arming_from_gcs)
     }
 
     // run pre-arm-checks and display failures
-    if (!arming.all_checks_passing(arming_from_gcs)) {
+    if (do_arming_checks && !arming.all_checks_passing(arming_from_gcs)) {
         AP_Notify::events.arming_failed = true;
         in_arm_motors = false;
         return false;