AP_Scripting: add mission scripting example

libraries/AP_Scripting/examples/Mission_test.lua

@@ -0,0 +1,49 @@
+-- This script is a test for AP_Mission bindings
+
+local last_mission_index = mission:get_current_nav_index()
+
+function update() -- this is the loop which periodically runs
+
+  local mission_state = mission:state()
+
+  -- make sure the mission is running
+  if mission_state == mission.MISSION_COMPLETE then
+    gcs:send_text(0, "LUA: Mission Complete")
+    return update, 1000 -- reschedules the loop
+  elseif mission_state == mission.MISSION_STOPPED then
+    gcs:send_text(0, "LUA: Mission stopped")
+    return update, 1000 -- reschedules the loop
+  end
+
+  local mission_index = mission:get_current_nav_index()
+
+  -- see if we have changed since we last checked
+  if mission_index ~= last_mission_index then
+
+    gcs:send_text(0, "LUA: New Mission Item") -- we spotted a change
+
+    -- print the current and previous nav commands
+    gcs:send_text(0, string.format("Prev: %d, Current: %d",mission:get_prev_nav_cmd_id(),mission:get_current_nav_id()))
+
+    last_mission_index = mission_index;
+
+    -- num commands includes home so - 1
+    local mission_length = mission:num_commands() - 1
+    if mission_length > 1 and mission_index == mission_length then
+      local jump_to = 1
+      if mission_length > 2 then
+        -- jump back to a random mission item
+        jump_to = math.random(mission_length - 1)  -- no point jump to the end so - 1
+      end
+      if mission:set_current_cmd(jump_to) then
+        gcs:send_text(0, string.format("LUA: jumped to mission item %d",jump_to))
+      else
+        gcs:send_text(0, "LUA: mission item jump failed")
+      end
+    end
+  end
+
+  return update, 1000 -- reschedules the loop
+end
+
+return update() -- run immediately before starting to reschedule

libraries/AP_Scripting/generator/description/bindings.desc

@@ -200,7 +200,7 @@ singleton AP_Mission scheduler-semaphore
 singleton AP_Mission enum MISSION_STOPPED MISSION_RUNNING MISSION_COMPLETE
 singleton AP_Mission method state uint8_t
 singleton AP_Mission method get_current_nav_index uint16_t
-singleton AP_Mission method set_current_cmd boolean uint16_t 0 UINT16_MAX
+singleton AP_Mission method set_current_cmd boolean uint16_t 0 (ud->num_commands()-1) 
 singleton AP_Mission method get_prev_nav_cmd_id uint16_t
 singleton AP_Mission method get_current_nav_id uint16_t
 singleton AP_Mission method get_current_do_cmd_id uint16_t