AP_Scripting: Add example to automatically switch EFI generator on/off

libraries/AP_Scripting/examples/efi_gen_auto_switch.lua

@@ -0,0 +1,148 @@
+--[[
+    Switch EFI Generator on/off based on reported Load
+    This maybe useful when aircraft is flown using the gas engine and the electric generator is to power payloads and other auxilary equipment
+    Tested to be working in parallel with the  EFI_SkyPower lua script
+--]]
+
+-- Variables
+local lastSwitchTime_ms = millis() -- Time when the last switch occurred
+local generatorState = nil -- Current state of the generator (true = on, false = off)
+local aboveThresholdTime_ms = 0 -- Time (in ms) engine load has remained above the threshold
+local belowThresholdTime_ms = 0 -- Time (in ms) engine load has remained below the threshold
+local update_rate_ms = 100
+
+PARAM_TABLE_KEY = 120
+PARAM_TABLE_PREFIX = "EFIGEN_"
+
+-- bind a parameter to a variable given
+function bind_param(name)
+    local p = Parameter()
+    assert(p:init(name), string.format('could not find %s parameter', name))
+    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))
+    return bind_param(PARAM_TABLE_PREFIX .. name)
+end
+
+-- Setup EFI Parameters
+assert(param:add_table(PARAM_TABLE_KEY, PARAM_TABLE_PREFIX, 6), 'could not add EFIGEN param table')
+
+--[[
+  // @Param: EFIGEN_ENABLE
+  // @DisplayName: Enable automatic EFI Generator on/off switch
+  // @Description: Enable automatic EFI Generator on/off switch
+  // @Values: 0:Disabled,1:Enabled
+  // @User: Standard
+--]]
+local EFIGEN_ENABLE = bind_add_param('ENABLE', 1, 0)
+
+--[[
+  // @Param: EFIGEN_GEN_FN
+  // @DisplayName: EFI generator control function
+  // @Description: EFI generator control function.
+  //               This is the RCn_OPTION value to use to find the R/C channel used for controlling generator start/stop
+  // @Values: 0:Disabled,300:300,301:301,302:302,303:303,304:304,305:305,306:306,307:307
+  // @User: Standard
+--]]
+local EFIGEN_FN = bind_add_param('FN', 2, 0) -- generator control function (RC option)
+
+--[[
+  // @Param: EFIGEN_MIN
+  // @DisplayName: EFI Generator Min Load
+  // EFI Generator will switch on if load is less than this parameter for EFIGEN_TIMER seconds
+  // @Range: 20 50
+  // @User: Standard
+--]]
+local EFIGEN_MIN = bind_add_param('MIN', 3, 45) -- generator control function (RC option)
+
+--[[
+  // @Param: EFIGEN_MAX
+  // @DisplayName: EFI Generator Max Load
+  // @Description: EFI Generator will switch off if load is greater than this parameter for EFIGEN_TIMER seconds
+  // @Range: 40 80
+  // @User: Standard
+--]]
+local EFIGEN_MAX = bind_add_param('MAX', 4, 55)
+
+
+--[[
+  // @Param: EFIGEN_TIMER
+  // @DisplayName: EFI Generator Switch Timer
+  // @Description: EFI Generator Load has to be greater than EFIGEN_MIN or less than EFIGEN_MAX for this many seconds
+  // @Range: 0 10
+  // @User: Standard
+--]]
+local EFIGEN_TIMER = bind_add_param('TIMER', 5, 2)
+
+
+--[[
+  // @Param: EFIGEN_TIMOU
+  // @DisplayName: EFI Generator Switch Timeout
+  // @Description: EFI Generator will not be switched on/off if it was previously switched within this many seconds
+  // @Range: 0 10
+  // @User: Standard
+--]]
+local EFIGEN_TIMOU = bind_add_param('TIMOU', 6, 5)
+
+
+function switchGenerator(state, load)
+  generatorState = state
+  lastSwitchTime_ms = millis()
+  if state then
+    gcs:send_text(2,"Generator switched ON. Current Load: " .. tostring(load))
+    rc:run_aux_function(EFIGEN_FN:get(), 2)
+  else
+    gcs:send_text(2,"Generator switched OFF. Current Load: " .. tostring(load))
+    rc:run_aux_function(EFIGEN_FN:get(), 0)
+  end
+end
+
+-- Function to check the EFI engine load
+function checkEngineLoad(loadPercent)
+  if loadPercent >= EFIGEN_MAX:get() then
+    aboveThresholdTime_ms = aboveThresholdTime_ms + update_rate_ms
+    belowThresholdTime_ms = 0
+    if aboveThresholdTime_ms >= EFIGEN_TIMER:get()*1000 and (generatorState or generatorState == nil) then
+      switchGenerator(false, loadPercent) -- Switch off the generator
+    end
+  elseif loadPercent <= EFIGEN_MIN:get() then
+    belowThresholdTime_ms = belowThresholdTime_ms + update_rate_ms
+    aboveThresholdTime_ms = 0
+    if belowThresholdTime_ms >= EFIGEN_TIMER:get()*1000 and (not generatorState or generatorState == nil) then
+      switchGenerator(true, loadPercent) -- Switch on the generator
+    end
+  else
+    aboveThresholdTime_ms = 0
+    belowThresholdTime_ms = 0
+  end
+end
+
+-- Function to check if enough time has passed since the last switch
+function enoughTimePassed()
+  local elapsedTime = millis() - lastSwitchTime_ms
+  return elapsedTime >= EFIGEN_TIMOU:get()*1000
+end
+
+function update()
+  if EFIGEN_ENABLE:get() == 0 then
+      return update, update_rate_ms
+  end
+
+  local efi_state = efi:get_state()
+  local load_percentage = efi_state:engine_load_percent()
+  if not load_percentage then
+      return update, update_rate_ms
+  end
+
+  if enoughTimePassed() then
+    checkEngineLoad(load_percentage)
+  end
+
+  return update, update_rate_ms
+end
+
+gcs:send_text(6, "Started EFI Gen Load Checker")
+return update()