How to set a script in the RaceCapture app

API Reference

OBDII tricks

Clear current trouble codes

This script clears any current trouble codes every 10 seconds. Clearing the code requires transmitting an OBDII command to ID 0x7DF with mode 4 specified. No other parameters are specified.

setTickRate(1) 
count = 0
function onTick()
 checkClearCodes()
end

function checkClearCodes()
  if count % 10 == 0 then
    print('clearing codes')
    txCAN(0, 0x7df, 0, {1,4})
  end
end

Query and Decode Diagnostic Trouble Code

This script queries for a DTC, and if found, prints the decoded trouble code and the raw data.

--This example queries for and reads the first available DTC, if present. 

setTickRate(1)

--P=Powertrain, C=Chassis, B=Body, U=Network
prefixes = {'P','C','B','U'}
digits = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'} 

function toDigit(v)
  return digits[v+1]
end

function printDTC(data)
  local dtc
  local a = data[3]
  local b = data[4]
  local prefix = prefixes[bit.band(bit.rshift(a, 6), 0x03) + 1]
  local c2 = bit.band(bit.rshift(a, 4), 0x03)
  local c3 = bit.band(a, 0x0f)
  local c4 = bit.band(bit.rshift(b, 4), 0x0F)
  local c5 = bit.band(b, 0x0F)

  local code = prefix ..toDigit(c2) ..toDigit(c3) ..toDigit(c4) ..toDigit(c5)
  println('Found DTC: ' ..code)  
end

function printRawDTC(data)
  print('Raw DTC bytes: ')
  --print the remaining 6 bytes, 
  --this raw data holds the trouble codes
  for i=1, #data do print(' ' ..data[i]) end
  println('')
end

function checkDTCResponse()
  local attempts = 0
  while attempts < 50 do
    local id,ext, data = rxCAN(0, 10)
    if id ~= nil and ext == 0 and id == 0x7e8 then
      if data[2] == 0x43 then
        if data[1] > 2 then
          printRawDTC(data)
          printDTC(data)
        else
          println('No DTC Found')
        end 
        return
      end
    end
    attempts = attempts + 1
  end
end

function sendCheckDTC()
  println('Sending check DTC')
  txCAN(0, 0x7df, 0, {1,3})
end

function onTick() 
  sendCheckDTC()
  checkDTCResponse()
end

Data filtering

Simple RPM Filter

Got a noisy RPM signal where big spikes show up? This will reject RPM values above a sane threshold.

Important - make sure the RPM channel in the main RaceCapture/Pro config is disabled, since this virtual channel replaces it.

--sample RPM at 10Hz
setTickRate(10)

--set this value to be your sane upper limit
rpmLimit = 10000

--In the RCP config, ensure the timer channels are disabled
--we will create the virtual channel here
rpmId = addChannel( "RPM", 10, 0, 0, rpmLimit)
rpm = 0

function doRPM()
  local r = getTimerRpm(0)
  if r < rpmLimit then 
    rpm = r
  end
  setChannel(rpmId, rpm)
end


function onTick()
  doRPM()
end

Automatic logging control

Automatically Start Logging When Powered On

This script will automatically start logging the moment RaceCapture/Pro turns on

Note, this will create a file with an incorrect timestamp if GPS lock is not established.
- To get a properly time-stamped file, use the GPS speed triggered approach.

function onTick()
  startLogging()
end

Automatically Start Logging based on GPS Speed

This script will automatically start logging to SD card when speed exceeds 10MPH and stop when it falls below.

function onTick()
  if getGpsSpeed() > 10 then
    startLogging()
  else
    stopLogging()
  end
end

Automatically Start Logging when engine is running

This script will automatically start logging to SD card when battery voltage shows that the engine is running

When battery voltage is greater than 13 volts, we assume engine is running.
System battery voltage is tied to the last Analog channel (8) (Note, change this to 7 if RaceCapture/Pro MK2)

function onTick()
  if getAnalog(8) > 13 then
    startLogging()
  else
    stopLogging()
  end
end

Automatically start Logging upon Launch (AutoX / Rally / Hill Climb)

This script will start Logging when a dash mounted "ARM" switch is activated via an input and G-force exceeds a threshold Given:

GPIO 0 configured as input and connected to dash mounted "Arm" switch
Default RaceCapture/Pro mounting orientation (terminal block facing forward, mounted upright)
G-force launch threshold is -0.1 G
flipping the ARM switch to 'Off' will stop logging

 setTickRate(30)
 overRevId = addChannel("OverRev", 10)


 function onTick()
  local arm = getGpio(0)
  local g = getAccel(1)
  if arm == 0 then
    stopLogging()
  end
  if arm == 1 and g < 0.1 then
    startLogging()
  end
 end

Virtual Channels (AKA Math Channels)

Averaging a fuel level reading or other sensor

This script calculates a moving average to account for fuel slosh. Assumptions:

Fuel level is connected to the first analog channel and is calibrated; modify the script to base the reading on other channels as appropriate.

--The real analog channel should be named
--something other than FuelLevel
fuel2Id = addChannel("FuelLevel", 10, 0, 0,100,"%")

--change this to make a bigger averaging window
maxAvg = 600 
--600 = 20 seconds averaging at 30Hz tick rate

--do not change
fuelAvg={}
fuel2Index = 1

function updateFuelAvg(value)
  local i
  if #fuelAvg == 0 then
    --initialize averaging table
    for i = 1, maxAvg do fuelAvg[i]=0 end
  end
  fuelAvg[fuel2Index] = value
  fuel2Index = fuel2Index + 1
  if fuel2Index > maxAvg then fuel2Index = 1 end
  local sum = 0
  for i = 1, #fuelAvg do
    sum = sum + fuelAvg[i]
  end
  setChannel(fuel2Id, sum / maxAvg)
end


setTickRate(30)
function onTick()
  updateFuelAvg(getAnalog(0))
end

Average two sensor values and set to a virtual channel

--10Hz update
setTickRate(10)

--Create channel: "SensorAvg"
--Sample rate: 10Hz
--Logging precision: 2 decimal points
--min/max: 0/5
--Units: "Volts"
avgId = addChannel("SensorAvg", 10, 2, 0, 5, "Volts")

function onTick()
  local a1 = getAnalog(0)
  local a2 = getAnalog(1)
  setChannel(avgId, (a1 + a2) / 2)
end

Gear Calculation

Calculate gear position based on drive train ratios, RPM channel and gear. Requires firmware 2.5.0

Edit the gear ratios to match your vehicle. Assumes Speed is available on "Speed" channel, RPM is available on "RPM" channel.

More details under the calcGear API documentation.

setTickRate(30)

--create gear channel
gearId = addChannel("Gear", 10, 0, 0, 6)

function onTick()
  -- calculate gear: tire diameter(cm), final gear ratio, individual gear ratios 1-6
  local gear = calcGear(62.7, 3.45, 4.23, 2.52, 1.66, 1.22, 1.0, 0.8)
  if gear == nil then gear = 0 end
  setChannel(gearId,gear)
end

Also available as a preset

Throttle Position Calculation

Estimate throttle position based on G-Forces. 0-100%

--Developed by Scott Barton of ProFormance Coaching for use by Autosport Labs Community

MaxAccelG = 0.30   -- Look at your logs and see what your max acceleration is in 3rd or 4th gear.  Note that full acceleration in 5th will not show 100% throttle.
chThrottle = addChannel("vThrottle", 10, 0, 0, 100,'')

function updatevThrottle()
--AccelG = getChannel(LongAccel) --2.13 Firmware and up
 AccelG = getImu(0) --Prior to 2.13 Firmware
 TPS = (AccelG/MaxAccelG)*100
 
 if TPS < 0 then TPS = 0 end
 TPS = math.abs(TPS)
 if TPS > 99 then TPS = 100 end
 setChannel(chThrottle, TPS)

end

--10Hz update
setTickRate(10)

function onTick()
  updatevThrottle()
end

Brake Position Calculation

Estimate brake pedal position based on G-Forces. 0-100%.

 --Developed by Scott Barton of ProFormance Coaching for use by Autosport Labs Community

MaxDecelG = 1.20   --Look at your logs and see what your maximum g-forces under straight line braking is and round down. 
chBrake = addChannel("vBrake", 10, 0, 0, 100, '')

function updatevBrake()
 --BrakeG = getChannel(LongAccel) -- 2.13 Firmware and up
 BrakeG = getImu(0) --Prior to 2.13 Firmware
--if ReverseAccel then 
BrakeG = BrakeG *-1
 --BrakeG = -1.1
 BrakePos = (BrakeG/MaxDecelG)*100
 
 if BrakePos < 10 then BrakePos = 0 end
 BrakePos = math.abs(BrakePos)
 if BrakePos > 99 then BrakePos=100 end
 setChannel(chBrake, BrakePos)
end

--10Hz update
setTickRate(10)

function onTick()
  updatevBrake()
end

Max RPM detection with GPIO reset

This script detects the peak RPM detected and stores it in a virtual channel. A GPIO is used to reset the channel to zero via a push button.

maxRpmId = addChannel("MaxRPM", 10)
maxRpm = 0

function rpmReset()
local rpm = getTimerRpm(0)
local clear = getGpio(0)
if rpm > maxRpm then
  maxRpm = rpm
  setChannel(maxRpmId, maxRpm)
end
if clear == 0 then
  maxRpm = 0
setChannel(maxRpmId, maxRpm)

end
end

function onTick()
rpmReset()
end

Alerts/Notifications

Create an over-rev marker

This script will mark the datalog with an over-rev alert marker whenever RPMs are above a certain threshold. Given:

RPM is connected to the first Timer input channel
RPM over-rev condition is 8000

setTickRate(10)
overRevId = addChannel("OverRev", 10)

function onTick()
  local rpm = getTimerRpm(0)
  local overRev = 0
  if rpm > 8000 then overRev = 1 end
  setChannel(overRevId, overRev)
end

Alert driver via electro-shock if oil pressure below safe threshold

This will alert driver via a shock (using pet scat mat) if oil pressure drops below threshold while engine is running above certain RPM

Script will check at 10Hz (10 times/sec) for threshold condition

Given:

Oil pressure on analog channel 0, and calibrated
Seat mounted pet scat mat installed in seat and controlled by GPIO 0 (GPIO switches ground when active)
GPIO 0 is configured for output mode
RPM is connected to timer input 0

--onTick() is called at 10Hz
setTickRate(10)
 

rpmThreshold = 2000
lowOilPressure = 15

function onTick()
  local shockDriver = 0
  if getTimerRpm(0) > rpmThreshold and getAnalog(0) < lowOilPressure then
    shockDriver = 1
  end
  setGpio(0, shockDriver)
end

Track Max RPM / Value

This script will track a channel's maximum value and set a new channel with that maximum. Given:

RPM is connected to the first Timer input channel

setTickRate(10)
maxRpmId = addChannel("MaxRPM", 10)
maxRpm = 0

function onTick()
  local rpm = getTimerRpm(0)
  if rpm > maxRpm then
    maxRpm = rpm
    setChannel(maxRpmId, maxRpm)
  end
end

Activate a GPIO when start finish line is crossed

This script will pulse one of the GPIO outputs when the start/finish line is detected. First, the onTick rate is set to 10hz, then setGpio() is called with the result of the call to getAtStartFinish()

setTickRate(10)

function onTick()
  if getAtStartFinish() == 1 then
    setGpio(0, 1)
  else
    setGpio(0, 0)
  end
end

or

setTickRate(10)

function onTick()
  setGpio(0, getAtStartFinish())
end

Temperature Warning Indicator Light

This script will activate an output if an analog input exceeds a threshold. It's assumed a temperature sensor is connected to the Analog input channel 0 and is calibrated.

More information: Installation Guide, Sensor Guide, Operation Guide

function onTick()
 if getAnalog(0) > 212 then
   setGpio(0, 1)
 else
   setGpio(0, 0)
 end
end

Multi warning light

A script to trigger a warning light if at least one condition occurs. This will activate the output if the engine temperature is greater than 212 or if oil pressure drops below 10.

Note Actual temperature and pressure sensors must be connected to the appropriate analog inputs and correctly calibrated.

--Analog 0 is engine temp, in degrees F
--Analog 1 is oil pressure, in PSI

function onTick()
 if getAnalog(0) > 212 or getAnalog(1) < 10 then
   setGpio(0, 1)
 else
   setGpio(0, 0)
 end
end

Enable an LED if fuel level drops below 10%

Using PWM/Analog output

only available on RaceCapture/Pro MK1 and MK2

- Fuel sensor is on Analog 0, scaled 0-100%
- LED indicator connected to PWM 0. When fuel level drops below 10%, Analog/PWM output 0 will show 5v; 0v if fuel level is higher
- PWM channel settings are set to factory default

function onTick()
 local p = 0
 if getAnalog(0) < 10 then p = 100 end
 setPwmDutyCycle(0,p)
end

Using GPIO in output mode
- When fuel level drops below 10%, the GPIO is activated (output is grounded). Can be used to drive a relay or other device up to 1A load
- GPIO jumper set to output mode
- GPIO setting in firmware set to match jumper setting

function onTick()
 local p = 0
 if getAnalog(0) < 10 then p = 1 end
 setGpio(0, p)
end

3 stage Sequential Shift Light

Activates a 3 stage sequential shift light. Also see the Sequential Shift Light project

Given:

RPM sensor on timer input 0
GPIO channels are configured in output mode under Setup/GPIO

setTickRate(15)

function onTick() 
	local r = getTimerRpm(0) 
	if r > 5000 then setGpio(2,1) else setGpio(2,0) end 
	if r > 6000 then setGpio(1,1) else setGpio(1,0) end 
	if r > 7000 then setGpio(0,1) else setGpio(0,0) end
end

ProFormance Meter

Uses ShiftX to show you how much available grip you are using and how much is left. It also creates and updates the ProFormace channel which is an integer from 0-9. Closer to 9 you are the closer you are to max available grip.

Instead of just using GSum, this takes into account that your MaxLatG's will be different than your MaxLongG's and gives you a more accurate representation of what you can do based on whether you are braking, turning, or accelerating.

It also has 2 different models. 1) for an Advanced Driver and 2) for a Pro Driver. This is based on typical friction circles of Advanced Drivers vs Pro Drivers respectively. See the OnTick funtion to change DriverLevel.

It also has an Oversteer Alert feature for ShiftX. Change the YawThreshold value to suit your needs.

setTickRate(25)
sxSetConfig(1)

yawThreshold = 25 --At what yaw rate do you want the oversteer alarm lights to trigger'  Check normal max yaw on your Podium.live race summaries to get a better idea of what value you should use   
flipBrakeAccel = false --set to true if you have your RC mounted backwards

maxGsumId = addChannel("MaxGsum", 25, 2, -2.0, 2.0)
pctGsumMaxId = addChannel("PctMaxGsum", 25, 0, 0, 100)
maxLatGId = addChannel("MaxLatG", 25, 2, -2.0, 2.0)
maxBrakeGId = addChannel("MaxBrakeG", 25, 2, -2.0, 2.0)
maxAccelGId = addChannel("MaxAccelG", 25, 2, -2.0, 2.0)
maxYawId = addChannel("MaxYaw", 25, 0, 0, 180) --Can remove this once you get an idea of what your YawThreshold should be
ProFormanceRatingId = addChannel("ProFormance", 25, 0, 9)

maxGsum = .3
maxLatG = .2
maxBrakeG = .2
maxAccelG = .1
maxYaw = 1
currLatG = 0
longG = 0
lastLongG = 0
lastLatG = 0
ProFormanceRating=0

function updateGStats()
	local gsum = getChannel("Gsum")
	if gsum ~= nil and gsum > 0 then
		if gsum > maxGsum then 
			maxGsum = gsum 
			setChannel(maxGsumId, maxGsum)		
		end
		setChannel(pctGsumMaxId, (gsum / maxGsum) * 100)
	end

	local latG = getChannel("AccelY")
	if latG ~= nil then
		latG = math.abs(latG)
		if latG > maxLatG then 
			maxLatG = latG 
			setChannel(maxLatGId, maxLatG)
		end
	end

	local currLongG = getChannel("AccelX")
	if currLongG ~= nil then
		if flipBrakeAccel then currLongG = currLongG*-1 end
		if currLongG>0 then
			if currLongG > maxBrakeG then 
				maxBrakeG = currLongG 
				setChannel(maxBrakeGId, maxBrakeG)
			end
		elseif currLongG<0 then
			currLongG = math.abs(currLongG)
			if currLongG>maxAccelG then
				maxAccelG = currLongG
				setChannel(maxAccelGId, maxAccelG)
			end
		end
	end
	
	--Can remove this Yaw section once you get an idea of what your YawThreshold should be
	local Yaw = getChannel("Yaw")
	if Yaw ~= nil then
		Yaw = math.abs(Yaw)
		if Yaw > maxYaw then 
			maxYaw = Yaw 
			setChannel(maxYawId, maxYaw)
		end
	end


end



function alertYaw(Yaw)  --Light up the side ShiftX lights in case of an Oversteer event
	if Yaw >= yawThreshold+20 then
		sxSetLed(7,2,255,255,255,9)
	elseif Yaw >= yawThreshold+10 then
		sxSetLed(7,2,255,255,255,5)
	elseif Yaw >= yawThreshold then
		sxSetLed(7,2,255,255,255,3)
	else
		sxSetLed(7,2,0,0,0,0)
	end

end


function resetSxLeds() --resets all the ShiftX lights to off
		sxSetLed(0,0,0,0,0,0)
end



function getProFormanceRating(driverLevel) --Calculate how much grip they are using and how much is left
	--driverLevel: 1=Advanced, 2=Pro
	
	local cLatG = getChannel("AccelY")
	if cLatG ~= nil then currLatG = math.abs(cLatG) end
	local cLongG =  getChannel("AccelX")
	if cLongG ~= nil then 
		longG = cLongG
		if flipBrakeAccel then longG = longG*-1 end
	end
	
	local BrakeAccel = "Braking"
	local maxLongG = maxBrakeG

	--may not want to do this
	--if longG <= -0.01 then 
	--	BrakeAccel = "Accelerating" 
	--	maxLongG = maxAccelG
	--end
	
	local currLongG = math.abs(longG)
		
	local percLatGUsed = currLatG/maxLatG --How much of maxLatG (max cornering G's) are we actually using right now
	local percLongGUsed = currLongG/maxLongG ---How much of maxLongG (max Braking/Accel G's) are we actually using right now
	local percLatGAvail = 1-percLongGUsed --Given current braking/accel G's (currLongG), how much cornering (LatG's) could we be doing?
	local percLongGAvail = 1-percLatGUsed -- Given current cornering G's (currLatG), how much braking or accelerating (LongG's) could we be doing?
	local currTotalG = math.sqrt((currLatG^2)+(currLongG^2)) -- GSum
	local currCombinedG = currLatG+currLongG 
	
	
	local totalLatGAvail = maxLatG - ((maxLatG-maxLongG)*percLongGUsed) 
	local totalLongGAvail = maxLongG - ((maxLongG-maxLatG)*percLatGUsed)
	
	--Models on how much grip is available is based on typical Friction Circle plots for Advanced Drivers vs Pro Drivers.  
	--Advanced drivers friction circle looks more like a triangle where currLatG+currLongG = maxGSum.  
	--Professional driver's firction circle looks more like a sideways D where SQRT((currLatG^2)+(currLongG^2)) = maxGsum
	--example: If maxGSum of a car is 1G, an advanced driver would do .5G braking and .5G cornering.  A pro driver in same car could do .7G braking and .7G cornering.
	--once a driver can consistently corner in the 8-9 ProFormance rating, they should use the Pro Driver setting
	local latGAvail = 0
	local longGAvail = 0
	if driverLevel==1 then --Advanced driver
		latGAvail =  maxLatG*percLatGAvail
		longGAvail = maxLongG*percLongGAvail
	else --Pro Driver
		latGAvail = math.sqrt((totalLatGAvail^2)-(currLongG^2))
		longGAvail = math.sqrt((totalLongGAvail^2)-(currLatG^2))
	end
	
	local percGUsedLat
	if latGAvail <= 0 then
		percGUsedLat = 1
	else
		percGUsedLat = currLatG/latGAvail
	end
	local totalGAvailLat = math.sqrt((currLongG^2)+(latGAvail^2))
	local combinedGAvailLat = currLongG+latGAvail
	 
	local percGUsedLong
	if longGAvail <= 0 then
		percGUsedLong = 1
	else
		percGUsedLong = currLongG/longGAvail
	end 
	
	local totalGAvailLong = math.sqrt((currLatG^2)+(longGAvail^2))
	local combinedGAvailLong = currLatG+longGAvail
	
	
	--local AvgLatPotential = (percLatGUsed+percGUsedLat)/2
	local TotalLatPot1 = percGUsedLong+(percLatGAvail*percGUsedLat)
	local TotalLatPot2
	if totalGAvailLat <= 0 then
		TotalLatPot2 = 1
	else
		TotalLatPot2 = currTotalG/totalGAvailLat
	end
	local TotalLatPot3
	if combinedGAvailLat <= 0 then
		TotalLatPot3 = 1
	else
		TotalLatPot3 = currCombinedG/combinedGAvailLat
	end
	local TotalLatPot4 = percGUsedLat+((1-percGUsedLat)*percLongGUsed)
	local avgTotLatPot = (TotalLatPot1+TotalLatPot2+TotalLatPot3+TotalLatPot4)/4
		
	--local AvgLongPotential = (percLongGUsed+percGUsedLong)/2 
	local TotalLongPot1 = percGUsedLat+(percLongGAvail*percGUsedLong)
	local TotalLongPot2
	if totalGAvailLong <= 0 then
		TotalLongPot2 = 1
	else
		TotalLongPot2 = currTotalG/totalGAvailLong
	end
	local TotalLongPot3
	if combinedGAvailLong <= 0 then
		 TotalLongPot3 = 1
	else
		TotalLongPot3 = currCombinedG/combinedGAvailLong
	end
	local TotalLongPot4 = percGUsedLong+((1-percGUsedLong)*percLatGUsed)
	local avgTotLongPot = (TotalLongPot1+TotalLongPot2+TotalLongPot3+TotalLongPot4)/4
	
	
	if currLongG-lastLongG > currLatG-lastLatG then
		ProFormanceRating = math.floor(avgTotLongPot*10)
	else
		ProFormanceRating = math.floor(avgTotLatPot*10)
	end
	if ProFormanceRating<0 then ProFormanceRating=0 end
	if ProFormanceRating>9 then ProFormanceRating=9 end
	setChannel(ProFormanceRatingId, ProFormanceRating)
	lastLongG = currLongG
	lastLatG = currLatG
	return ProFormanceRating
end



function showProFormanceSx(rating) --Show ProFormanceRating on ShiftX
	local numLeds=7 --How many LEDs on the ShiftX do you want to use for the ProFormance meter. Default is 7; the 7 in the middle
	resetSxLeds()
	sxSetLed(0,numLeds,255,0,0,0)
	local percLeds = (.1*rating*(numLeds+1))
	local greenLeds =math.floor(percLeds)
	if greenLeds>0 then sxSetLed(0,greenLeds,0,255,0,0) end
	if percLeds-greenLeds>0.61 then
		sxSetLed(greenLeds,1,100,100,0,2)
	end
	sxSetDisplay(0,rating)
end



function onTick()
	collectgarbage()
	resetSxLeds()
	updateGStats()
	--ProFormance driver level: 1=Advanced, 2=Pro
	local driverLevel = 1
	ProFormanceRating = getProFormanceRating(driverLevel)
	showProFormanceSx(ProFormanceRating)--Show ProFormance Rating on ShiftX
	
	if getChannel("Yaw")~=nil then Yaw = getChannel("Yaw") end
	if math.abs(Yaw)>yawThreshold-5 then alertYaw(math.abs(Yaw)) end
end

CAN bus scripts

Receive a CAN message on one bus and re-transmit on a different bus

setTickRate(30)
function onTick()
  id, ext, data = rxCAN(0)
  if (id ~= nil) then
    txCAN(1, id, ext, data)
  end
end

Send A CAN message with current GPS speed

Given:

Destination CAN device is looking for a message with ID 1234
Standard (11 bit) CAN identifer
CAN1 channel is used

function onTick()
  local speed = getGpsSpeed()
  --format the speed in a CAN message. Speed is in the first byte
  local msg = {speed} 
  txCAN(0, 1234, 0, msg)
end

Send A CAN message with a temperature value

available in future Firmware version 2.0

Given:

Analog 0 reads a calibrated temperature value between 0 and 255
Destination CAN device is looking for a message with ID 1234
Standard (11 bit) CAN identifer
CAN1 channel is used

function onTick()
  local tmp = getAnalog(0)
  local msg = {tmp}
  txCAN(0, 1234, 0, msg)
end

Use RCP as a general purpose CAN data logger

The following script will output any received CAN bus message to the log window.

You can access the log window by enabling polling in the script window under the RaceCapture app configuration view
You can also access the log window by connecting to RaceCapture/Pro from a terminal program (hyperterminal, Minicom, etc) and issuing the command: viewLog

setTickRate(30) --30Hz

function onTick()
    repeat --will drain CAN buffer on each tick
        id, e, data = rxCAN(0)
	if id ~= nil then
		print(id ..':')
		for i=1,#data do
			print(data[i] ..' ')
		end
		println('')
	end
    until id == nil
end

Receive a CAN message and set a virtual channel

Given:

creates a channel named "MyChannel" that logs at 10Hz
Sets tick rate to 10Hz
Receive a CAN message on CAN1 channel, with 100ms timeout
if data received is valid (by checking the CAN message ID is not nil), then set the virtual channel with the first element in the CAN message data

channelId = addChannel("MyChannel", 10)
setTickRate(10)

function onTick()
  id, ext, data = rxCAN(0, 100)
  if id ~= nil then
    setChannel(channelId, data[1])
  end
end

Note: To map real CAN bus data, consult your CAN bus protocol documentation for correctly mapping CAN bus data to virtual channels.

CAN bus loopback test

Use This script to test functionality of your CAN bus.

Wiring / Setup

Connect CAN1 high -> CAN2 high and CAN1 low -> CAN2 low. This can either be done though the main wiring harness or the RJ45 connector.
- Note if your unit has CAN on the wiring harness and the RJ45 connector, you only need to bridge the connections on one harness, since they are internally wired together.
Set the CAN baud rates to the same value for CAN1 and CAN 2.

-- CAN loopback test
-- * Wire CAN1 high -> CAN2 high and CAN 1 low -> CAN 2 low
-- * Ensure baud rate is identical for both CAN1 and CAN2
can_id = 1234
count = 0
function onTick() 
  count = count + 1
  -- transmit a CAN message on CAN1 with count as the first byte
  local tx_result = txCAN(0, can_id, 0, {count})
  println('transmit result ' ..tx_result)

  -- receive a CAN message on CAN2  
  local id, ext, data = rxCAN(1)

  if id == nil then
    println('No CAN message received!')
  else
    println('Got CAN message ID: ' ..id ..' data: ' ..data[1])
  end
end

Serial Port

Read an analog sensor value and output it to the auxiliary serial port

This example reads an analog sensor and writes a string containing the value to the Auxiliary serial port. Repeats once per second.

--initialize Aux serial port to 115200, 8, N, 1
initSer(4, 115200, 8, 0, 1)

function onTick()
 value = getAnalog(0)
 writeSer(4, 'A=' ..value)
end

Read a line of serial data

This example reads a line of serial data and writes it to the internal RaceCapture log.

Note: You can monitor the log by enabling the log polling in the script configuration view.

--initialize Aux serial port to 115200, 8, N, 1
initSer(4, 115200, 8, 0, 1)

function onTick()
 --read a line from the aux serial port with a 100ms timeout
 value = readSer(4, 100)
 if value ~= nil then
  println('read value: ' ..value)
 end
end

Demo Scripts

RPM Sweep

This sweeps an RPM channel up and down through a pre-defined range. Edit the range at the top of the script.

-- 05 Jan 2016 RPM demo
-- F.Mirandola - B.Picasso
-- This code will show a demo RPM sweep on RaceCapturePro

thrRpmLo = 3000
 --Low RPM threshold for change direction
 
thrRpmHi = 10000
--Hi RPM threshold for change direction
incrementRpm = 300
--Step between each RPM increment/decrement, will affect the speed, higher = faster

-- Do not edit after this!!

setTickRate(10)

rpm = 0

direction = 0

rpmId = addChannel("RPM", 10, 0, 0, 10000)

function onTick()
  setChannel(rpmId, rpm)

  if (rpm<=thrRpmHi and direction == 0 ) then rpm = rpm + incrementRpm  
  	elseif (rpm>=thrRpmLo and direction == 1 ) then rpm = rpm - incrementRpm
  end

  if (rpm>thrRpmHi) then direction = 1
   	elseif (rpm<thrRpmLo) then direction = 0
  end

end

Simulating Laps

Here's a neat script that can simulate lap times and predicted times. We've used it to develop dashboard features for the app. Especially interesting is the use of the accelerometer to generate a bit of noise and variability in the data.

--Script to simulate lap and predicted times
--Without needing a moving car on race track!
--To use, disable Race Timing in RaceCapture/Pro configuration and
--use this script
etid = addChannel("ElapsedTime", 10, 4)
ltid = addChannel("LapTime", 10, 4)
ptid = addChannel("PredTime", 10, 4)
clid = addChannel("CurrentLap", 10, 0)
lcid = addChannel("LapCount", 10, 0)

et = 0 --ElapsedTime value
lt = 0 --LapTime value
pt = 0 --PredTime value
cl = 0 --CurrentLap value
lc = 0 --LapCount value

targetTime = 0.5 --target time for our fake laps

setTickRate(10)
function onTick()

local rnd = getImu(0) --use the IMU to create a random-ish number

--simulate a predicted time if we've already
--completed a lap
--rnd value makes the predicted time jiggle
if lc > 0 then 
 pt = targetTime + rnd
 setChannel(ptid, pt)
end

--increment elapsed time by 1/10 second
et = et + 0.00166666667
setChannel(etid, et)

if et > targetTime + rnd then
 lt = et
 setChannel(ltid, lt)
 et = 0
 cl = cl + 1
 setChannel(clid, cl)
 if cl > 1 then
  lc = lc + 1
  setChannel(lcid, lc)
 end
end


end

RaceCapturePro Lua Scripting Examples

How to set a script in the RaceCapture app

API Reference

OBDII tricks

Clear current trouble codes

Query and Decode Diagnostic Trouble Code

Data filtering

Simple RPM Filter

Automatic logging control

Automatically Start Logging When Powered On

Automatically Start Logging based on GPS Speed

Automatically Start Logging when engine is running

Automatically start Logging upon Launch (AutoX / Rally / Hill Climb)

Virtual Channels (AKA Math Channels)

Averaging a fuel level reading or other sensor

Average two sensor values and set to a virtual channel

Gear Calculation

Throttle Position Calculation

Brake Position Calculation

Max RPM detection with GPIO reset

Alerts/Notifications

Create an over-rev marker

Alert driver via electro-shock if oil pressure below safe threshold

Track Max RPM / Value

Activate a GPIO when start finish line is crossed

Temperature Warning Indicator Light

Multi warning light

Enable an LED if fuel level drops below 10%

3 stage Sequential Shift Light

ProFormance Meter

CAN bus scripts

Receive a CAN message on one bus and re-transmit on a different bus

Send A CAN message with current GPS speed

Send A CAN message with a temperature value

Use RCP as a general purpose CAN data logger

Receive a CAN message and set a virtual channel

CAN bus loopback test

Wiring / Setup

Serial Port

Read an analog sensor value and output it to the auxiliary serial port

Read a line of serial data

Demo Scripts

RPM Sweep

Simulating Laps