AP_Scripting: add an example to use Copter Standby mode in SITL with LUA

libraries/AP_Scripting/examples/sitl_standby_sim.lua

@@ -0,0 +1,87 @@
+-- This script is a allow to switch the standby function by the switch of the remote controller on 2 simulated fcus.
+
+-- variable to limit the number of messages sent to GCS
+local last_rc_input = 0
+
+-- constants
+local switch_high = 2
+local switch_low = 0
+
+-- Standby function number in ArduPilot
+local standby_function = 76
+-- RC pin to use to select the FCU
+local rc_input_pin = 8
+
+
+-- for fast param access it is better to get a param object,
+-- this saves the code searching for the param by name every time
+local JSON_MASTER = Parameter()
+if not JSON_MASTER:init('SIM_JSON_MASTER') then
+  gcs:send_text(6, 'get SIM_JSON_MASTER failed')
+end
+
+local SYSID_THISMAV = Parameter()
+if not SYSID_THISMAV:init('SYSID_THISMAV') then
+  gcs:send_text(6, 'get SYSID_THISMAV failed')
+end
+
+local sysid = SYSID_THISMAV:get()
+
+gcs:send_text(6, 'LUA: Standby LUA loaded')
+
+-- The loop check the value of the switch of the remote controller and switch the standby function of the simulated fcus.
+-- FCU should have SYSID_THISMAV set to 1 or 2.
+-- The switch is on the channel 8 (default) of the remote controller.
+-- fcu1 and fcu2 have mirrored standby function, so only one is active at a time.
+-- As this is for simulation, the SIM_JSON_MASTER param is also update to select which fcu control the motors.
+
+function update() -- this is the loop which periodically runs
+  rc_input = rc:get_pwm(rc_input_pin)
+
+  if rc_input == nil then
+    gcs:send_text(6, 'LUA: rc_input is nil')
+    return update, 1000 -- reschedules the loop
+  end
+
+  if rc_input ~= last_rc_input then
+      if sysid == 2 then
+          if rc_input > 1500 then
+              if not JSON_MASTER:set(0) then
+                  gcs:send_text(6, string.format('LUA: failed to set SIM_JSON_MASTER'))
+              else
+                  rc:run_aux_function(standby_function, switch_high)
+                  gcs:send_text(6, string.format('LUA: set SIM_JSON_MASTER to 0'))
+              end
+          else
+              if not JSON_MASTER:set(1) then
+                  gcs:send_text(6, string.format('LUA: failed to set SIM_JSON_MASTER'))
+              else
+                  rc:run_aux_function(standby_function, switch_low)
+                  gcs:send_text(6, string.format('LUA: set SIM_JSON_MASTER to 1'))
+              end
+          end
+      end
+      if sysid == 1 then
+          if rc_input > 1500 then
+              if not JSON_MASTER:set(0) then
+                  gcs:send_text(6, string.format('LUA: failed to set SIM_JSON_MASTER'))
+              else
+                  rc:run_aux_function(standby_function, switch_low)
+                  gcs:send_text(6, string.format('LUA: set SIM_JSON_MASTER to 0'))
+              end
+          else
+              if not JSON_MASTER:set(1) then
+                  gcs:send_text(6, string.format('LUA: failed to set SIM_JSON_MASTER'))
+              else
+                  rc:run_aux_function(standby_function, switch_high)
+                  gcs:send_text(6, string.format('LUA: set SIM_JSON_MASTER to 1'))
+              end
+          end
+      end
+      last_rc_input = rc_input
+  end
+
+  return update, 1000 -- reschedules the loop
+end
+
+return update() -- run immediately before starting to reschedule