From df90b640ca5ab2e36158bb9898256fb7fbbef934 Mon Sep 17 00:00:00 2001
From: Henry Wurzburg <hwurzburg@yahoo.com>
Date: Tue, 27 Dec 2022 18:28:36 -0600
Subject: [PATCH] AP_Scripting:Add parameter controller applet

---
 .../AP_Scripting/applets/Param_Controller.lua | 94 +++++++++++++++++++
 .../AP_Scripting/applets/Param_Controller.md  |  9 ++
 2 files changed, 103 insertions(+)
 create mode 100644 libraries/AP_Scripting/applets/Param_Controller.lua
 create mode 100644 libraries/AP_Scripting/applets/Param_Controller.md

diff --git a/libraries/AP_Scripting/applets/Param_Controller.lua b/libraries/AP_Scripting/applets/Param_Controller.lua
new file mode 100644
index 0000000000..bb9764369f
--- /dev/null
+++ b/libraries/AP_Scripting/applets/Param_Controller.lua
@@ -0,0 +1,94 @@
+--[[
+   a script to select other parameters using an auxillary switch
+   from subdirectories in scripts directory labeled /1,/2, or /3
+--]]
+
+local SEL_CH = 302
+local PARAM_FILENAME = "params.param"
+
+--[[
+   check that directory exists
+--]]
+function check_subdir_exists(n)
+  return dirlist(get_scripts_dir() .. "/" .. n )
+end
+
+--[[
+   get the path to the scripts directory. This will be scripts/ on SITL
+   and APM/scripts on a ChibiOS board
+--]]
+function get_scripts_dir()
+   local dlist1 = dirlist("APM/scripts")
+   if dlist1 and #dlist1 > 0 then
+      return "APM/scripts"
+   end
+   -- otherwise assume scripts/
+   return "scripts"
+end
+
+--[[
+load parameters from a file PARAM_FILENAME from directory n
+--]]
+function param_load(n)
+   count = 0
+   failed = false
+   file_name = get_scripts_dir() .. "/" .. n .."/" .. PARAM_FILENAME
+  -- Open file
+  file = io.open(file_name)
+  if not file then
+     gcs:send_text(0,string.format("%s not present",file_name))
+     return
+  end
+   while true do
+      local line = file:read()
+      if not line then
+         break
+      end
+      -- trim trailing spaces
+      line = string.gsub(line, '^(.-)%s*$', '%1')
+      local _, _, parm, value = string.find(line, "^([%w_]+)%s*([%d]*.[%d]*)")
+      if parm then
+         if not param:set(parm,value) then
+            failed = true
+         else
+            count = count +1
+         end
+      end
+   end 
+   if not failed then
+      gcs:send_text(6,string.format("Loaded %u parameters",count)) 
+   else
+      gcs:send_text(6,string.format("Loaded %u parameters but some params did not exist to set",count)) 
+   end
+end   
+ 
+local sw_last = -1
+local load_param = true
+
+function update()
+   local sw_current = rc:get_aux_cached(SEL_CH)
+   if (sw_current == sw_last) or (sw_current == nil) then
+      return update, 500
+   end
+   if sw_current == 0 then 
+        subdir = 1
+      elseif sw_current == 2 then
+        subdir = 3
+      else
+        subdir = 2
+   end
+   sw_last = sw_current
+   if not check_subdir_exists(subdir) then
+      gcs:send_text(0,string.format("Scripts subdirectory /%s does not exist!",subdir))
+      return update, 500
+   end
+   if load_param then
+      param_load(subdir)
+      load_param = false
+   end
+   
+   return update, 500
+end
+
+gcs:send_text(5,"Loaded Parameter_Controller.lua")
+return update, 500
diff --git a/libraries/AP_Scripting/applets/Param_Controller.md b/libraries/AP_Scripting/applets/Param_Controller.md
new file mode 100644
index 0000000000..9a028a326a
--- /dev/null
+++ b/libraries/AP_Scripting/applets/Param_Controller.md
@@ -0,0 +1,9 @@
+# Param_Controller LUA script
+
+This script allows the user to have different parameters (in files named "params.parm") in three subdirectories of the main scripting directory and load them based on the position of a switch with the auxiliary function of "302". This allows easy, at the field selection of parameter sets. It uses the same switch function and directories as the Scripting_Controller.lua script selector and the two may be used together, if desired.
+
+# Setup and Operation
+
+The user must setup an RCx_OPTION to function 302 to determine which of the three scripts subdirectories will be used: LOW:scripts/1, MIDDLE:scripts/2, or HIGH:scripts/3. If no RC has been established during ground start, it will behave as if subdirectory 1 is selected. Changing this switch position either prior to ground start or after, will load a "params.param" file from the desginated subdirectory (if it and its subdirectory exists). Mission Planner also provides a means of executing the same function as an RC switch assigned to 302 in its AUX Function tab, so a transmitter switch does not necessarily need to be used.
+
+Note that loaded parameter changes are not saved across reboots, that must be done manually.