AntennaTracker: now supports mavlink arm and disarm commands to disable antenna servo outputs

Tools/AntennaTracker/GCS_Mavlink.pde

@@ -866,6 +866,22 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
                 break;
             }
 
+        case MAV_CMD_COMPONENT_ARM_DISARM:
+            if (packet.target_component == MAV_COMP_ID_SYSTEM_CONTROL) {
+                if (packet.param1 == 1.0f) {
+                    arm_servos();
+                    result = MAV_RESULT_ACCEPTED;
+                } else if (packet.param1 == 0.0f)  {
+                    disarm_servos();
+                    result = MAV_RESULT_ACCEPTED;
+                } else {
+                    result = MAV_RESULT_UNSUPPORTED;
+                }
+            } else {
+                result = MAV_RESULT_UNSUPPORTED;
+            }
+            break;
+
             case MAV_CMD_PREFLIGHT_REBOOT_SHUTDOWN:
             {
                 if (packet.param1 == 1 || packet.param1 == 3) {

Tools/AntennaTracker/system.pde

@@ -72,10 +72,8 @@ static void init_tracker()
     channel_yaw.calc_pwm();
     channel_pitch.calc_pwm();
 
-    channel_yaw.enable_out();
-    channel_pitch.enable_out();
-
     home_loc = get_home_eeprom(); // GPS may update this later
+    arm_servos();
 
     gcs_send_text_P(SEVERITY_LOW,PSTR("\nReady to track."));
     hal.scheduler->delay(1000); // Why????
@@ -191,3 +189,15 @@ static void set_home(struct Location temp)
     set_home_eeprom(temp);
     home_loc = temp;
 }
+
+static void arm_servos()
+{
+    channel_yaw.enable_out();
+    channel_pitch.enable_out();
+}
+
+static void disarm_servos()
+{
+    channel_yaw.disable_out();
+    channel_pitch.disable_out();
+}