```

function getBitRange(data, bitIndex, bitWidth)
	byteIndex = bitIndex >> 3
	shift = bitIndex - byteIndex * 8
	value = data[1 + byteIndex]
	if (shift + bitWidth > 8) then
		value = value + data[2 + byteIndex] * 256
	end
	mask = (1 << bitWidth) - 1
	return (value >> shift) & mask
end 

-- sometimes we want to cut a CAN bus and install rusEFI into that cut
-- https://en.wikipedia.org/wiki/Man-in-the-middle_attack

-- this controls onCanRx rate as well!
setTickRate(300)

ECU_BUS = 1
-- really 'not ECU'
TCU_BUS = 2

function setTwoBytes(data, offset, value)
		value = math.floor(value)
		data[offset + 2] = value >> 8
		data[offset + 1] = value & 0xff
	end

hexstr = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, "A", "B", "C", "D", "E", "F" }

function toHexString(num)
	if num == 0 then
		return '0'
	end

	local result = ""
	while num > 0 do
		local n = num % 16
		result = hexstr[n + 1] ..result
		num = math.floor(num / 16)
	end
	return result
end

function arrayToString(arr)
	local str = ""
	local index = 1
	while arr[index] ~= nil do
		str = str.." "..toHexString(arr[index])
		index = index + 1
	end
	return str
end

totalEcuMessages = 0
totalTcuMessages = 0

motor1Data = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }

function onMotor1(bus, id, dlc, data)
    rpm = getBitRange(data, 16, 16) * 0.25
    tps = getBitRange(data, 40, 8) * 0.4
    
    fakeTorque = interpolate(0, 6, 100, 60)
    
    -- engineTorque = getBitRange(data, 8, 8) * 0.39
    -- innerTorqWithoutExt = getBitRange(data, 32, 8) * 0.4
    -- torqueLoss = getBitRange(data, 48, 8) * 0.39
    -- requestedTorque = getBitRange(data, 56, 8) * 0.39
    
    engineTorque = fakeTorque;
    innerTorqWithoutExt = fakeTorque;
    torqueLoss = 10;
    requestedTorque = fakeTorque;
    
       	motor1Data[2] = engineTorque / 0.39
	setTwoBytes(motor1Data, 2, rpm / 0.25)
	motor1Data[5] = innerTorqWithoutExt / 0.4
 	motor1Data[6] = tps / 0.4
	motor1Data[7] = torqueLoss / 0.39
	motor1Data[8] = requestedTorque / 0.39
   
    
    print ('engineTorque ' .. engineTorque .. ' RPM ' .. rpm)
    print ('innerTorqWithoutExt ' .. innerTorqWithoutExt .. ' tps ' .. tps)
    
    print ('torqueLoss ' .. torqueLoss ' requestedTorque ' .. requestedTorque)
    
end


function printAndDrop(bus, id, dlc, data)
    print('Dropping ' ..arrayToString(data))
end

function onAnythingFromECU(bus, id, dlc, data)
    totalEcuMessages = totalEcuMessages + 1
    txCan(TCU_BUS, id, 0, data) -- relay non-TCU message to TCU
end

function onAnythingFromTCU(bus, id, dlc, data)
    totalTcuMessages = totalTcuMessages + 1
    txCan(ECU_BUS, id, 0, data) -- relay non-ECU message to ECU
end

-- VAG Motor_1 just as example
 canRxAdd(ECU_BUS, 0x280, onMotor1)

-- last option: unconditional forward of all remaining messages
canRxAddMask(ECU_BUS, 0, 0, onAnythingFromECU)
canRxAddMask(TCU_BUS, 0, 0, onAnythingFromTCU)

everySecondTimer = Timer.new()

function onTick()
    if everySecondTimer:getElapsedSeconds() > 1 then
        everySecondTimer:reset()
        print("Total from ECU " .. totalEcuMessages .. " from TCU " .. totalTcuMessages)
    end
end



```