rusefi_documentation/luaCanRxWorkaround.md

luaCanRxWorkaround

By default Lua CAN RX is easy but has a performance limitation.

If 300hz and above Lua CAN RX is needed until a more elegant solution is implemented https://github.com/rusefi/rusefi/issues/6041 we have luaCanRxWorkaround magic option.

For the magic to work two lines are required in the Lua script:

global_can_data = { } on top

and at least one global_can_data[1] read access to global_can_data anywhere in the script

rxCount = 0

-- magic behind the scenes: luaCanRxWorkaround on ParkingLot2 dialog
global_can_data = { }

function onVehicleDetect(bus, id, dlc, data)
	rxCount = rxCount + 1
	if rxCount < 10 then
-- at least one read from global_can_data to prevent garbage collection
		print('onVehicleDetect ' ..id .." " ..global_can_data[1])

	end
end

canRxAddMask(0, 0xFFFFFF00, onVehicleDetect)

everySecondTimer = Timer.new()
keepAlive = 0

function onTick()
	if everySecondTimer : getElapsedSeconds() > 1 then
		everySecondTimer : reset()
		keepAlive = keepAlive + 1
		print("Alive seconds=" ..keepAlive .. " rxCount " .. rxCount )
	end
end

Give us 2024-02-25_09_12_32_236: EngineState: LUA: Alive seconds=4 rxCount 596 2024-02-25_09_12_33_240: EngineState: LUA: Alive seconds=5 rxCount 912 2024-02-25_09_12_34_352: EngineState: LUA: Alive seconds=6 rxCount 1166 2024-02-25_09_12_35_357: EngineState: LUA: Alive seconds=7 rxCount 1420 2024-02-25_09_12_36_467: EngineState: LUA: Alive seconds=8 rxCount 1775 2024-02-25_09_12_37_577: EngineState: LUA: Alive seconds=9 rxCount 2030 2024-02-25_09_12_38_577: EngineState: LUA: Alive seconds=10 rxCount 2280 2024-02-25_09_12_39_582: EngineState: LUA: Alive seconds=11 rxCount 2605 2024-02-25_09_12_40_588: EngineState: LUA: Alive seconds=12 rxCount 2851 2024-02-25_09_12_41_592: EngineState: LUA: Alive seconds=13 rxCount 3076