AP_Scripting: update switch_rates.lua based on review comments

libraries/AP_Scripting/applets/switch_rates.lua

@@ -2,9 +2,6 @@
    rate switch utility. This helps to compare different tunes in-flight to compare performance
 --]]
 
----@diagnostic disable: param-type-mismatch
-
-
 local MAV_SEVERITY = {EMERGENCY=0, ALERT=1, CRITICAL=2, ERROR=3, WARNING=4, NOTICE=5, INFO=6, DEBUG=7}
 
 local PARAM_TABLE_KEY = 33
@@ -14,19 +11,10 @@ local PARAM_BACKUP_TABLE_PREFIX = "X_"
 
 local UPDATE_RATE_HZ = 4
 
--- bind a parameter to a variable, old syntax to support older firmware
-function bind_param(name)
-   local p = Parameter()
-   if not p:init(name) then
-      return nil
-   end
-   return p
-end
-
 -- add a parameter and bind it to a variable
 function bind_add_param(name, idx, default_value)
    assert(param:add_param(PARAM_TABLE_KEY, idx, name, default_value), string.format('could not add param %s', name))
-   local p = bind_param(PARAM_TABLE_PREFIX .. name)
+   local p = Parameter(PARAM_TABLE_PREFIX .. name)
    assert(p, string.format("could not find parameter %s", name))
    return p
 end
@@ -36,7 +24,7 @@ function bind_add_backup_param(name, idx, default_value)
    -- shorten pname to fit with X_ prefix
    local short_name = string.sub(name, math.max(1, 1 + string.len(name) - (16 - string.len(PARAM_BACKUP_TABLE_PREFIX))))
    assert(param:add_param(PARAM_BACKUP_TABLE_KEY, idx, short_name, default_value), string.format('could not add param %s', short_name))
-   local p = bind_param(PARAM_BACKUP_TABLE_PREFIX .. short_name)
+   local p = Parameter(PARAM_BACKUP_TABLE_PREFIX .. short_name)
    assert(p, string.format("could not find parameter %s", PARAM_BACKUP_TABLE_PREFIX .. short_name))
    return p
 end
@@ -146,7 +134,7 @@ local AuxSwitchPosNames = {"LOW", "MIDDLE", "HIGH"}
 -- start in LOW start
 local prev_pos = AuxSwitchPos.LOW
 
--- main update function
+-- main update function, called at 10Hz
 function update()
    local sw_pos = rc:get_aux_cached(PREV_RC_FUNC:get())
 
@@ -155,22 +143,8 @@ function update()
       gcs:send_text(MAV_SEVERITY.INFO, string.format("Rate switch: %u parameters changed to %s", count, AuxSwitchPosNames[sw_pos + 1]))
       prev_pos = sw_pos
    end
-end
-
--- wrapper around update(). This calls update() at 10Hz,
--- and if update faults then an error is displayed, but the script is not
--- stopped
-function protected_wrapper()
-  local success, err = pcall(update)
-  if not success then
-     gcs:send_text(MAV_SEVERITY.EMERGENCY, "Rate switch: internal Error: " .. err)
-     -- when we fault we run the update function again after 1s, slowing it
-     -- down a bit so we don't flood the console with errors
-     --return protected_wrapper, 1000
-     return
-  end
-  return protected_wrapper, 1000/UPDATE_RATE_HZ
+   return update, 1000/UPDATE_RATE_HZ
 end
 
 -- start running update loop
-return protected_wrapper()
+return update()