AP_Scripting: add example of arming check for wp index = 1 and is a takeoff

libraries/AP_Scripting/examples/arming-check-wp1-takeoff.lua

@@ -0,0 +1,29 @@
+-- This script runs a custom arming check for index == 1 and it must be a takeoff missionn item
+
+local auth_id = arming:get_aux_auth_id()
+
+local MAV_CMD_NAV_TAKEOFF = 22
+local MAV_CMD_NAV_VTOL_TAKEOFF = 84
+
+function update() -- this is the loop which periodically runs
+  if auth_id then
+    local cmd_id = mission:get_current_nav_id()
+    local index = mission:get_current_nav_index()
+
+    if not cmd_id or not index then
+      arming:set_aux_auth_failed(auth_id, "Could not retrieve mission")
+    elseif ((index ~= 0) and (index ~= 1)) then
+      -- index of 0 is valid because when you switch to AUTO it will automatically change to 1
+      arming:set_aux_auth_failed(auth_id, "Mission index is not ready")
+    elseif ((cmd_id ~= MAV_CMD_NAV_TAKEOFF) and (cmd_id ~= MAV_CMD_NAV_VTOL_TAKEOFF)) then
+      arming:set_aux_auth_failed(auth_id, "Mission is not ready to takeoff")
+    else
+      arming:set_aux_auth_passed(auth_id)
+    end
+  end
+  return update, 2000 -- reschedules the loop in 2 seconds
+end
+
+return update() -- run immediately before starting to reschedule
+
+