LITTLE DDU — Documentation

WHAT IT IS

The essentials and nothing else, in minimal LEDs, so it doesn't cost you a single frame. Built for VR, where every fps counts.

Three things:

  · the braking countdown
  · the metres left to the next corner
  · the temperature of all four tyres

Free.

THE BAR

ROW 1 · the small countdown LEDs and the BIG LED.

  The big LED shows the METRES left until the next braking point or
  lift, and switches to BRAKE when it's time.

  The colour tells you how hard it's going to be:
    BLUE      lift only, no brake
    GREEN     gentle brake
    YELLOW    medium
    ORANGE    hard
    RED       maximum

ROW 2 · the 4 TYRE TEMPERATURES, two on each side, laid out like the car's wheels: the side of the screen is the real side.

  Their colour:
    FLASHING BLUE   below 50° — frozen tyres, careful
    BLUE            50-55°
    TURQUOISE       55-60°
    GREEN           60-75° — working temperature
    YELLOW          75-85°
    ORANGE          85-95°
    RED             95-110°
    FLASHING RED    over 110° — way past it

WHAT REALLY MATTERS · THE TEMPERATURE IS AN ESTIMATE

This is worth understanding.

iRacing only updates tyre temperature when your crew measures it — that is, when you come through your pit box. Out on track that number stays FROZEN. If we showed it as-is, you'd see the same value lap after lap.

LITTLE does something else: it starts from the last real measurement and moves it with what you are actually doing:

  HEATS UP   braking (mostly the front axle), traction (mostly the
             rear) and cornering load (mostly the outside)
  COOLS      towards ambient temperature, faster the more air it gets
             (the faster you go)

And it SELF-CALIBRATES: every time you come back to the pits it compares what it had estimated against what is really measured, and corrects itself. The more you drive, the sharper it gets. The correction is kept from one session to the next.

⚠ It is an ESTIMATE, not a measurement. It is there for trends (they're cooling down, the front right is overheating) and to stop you going out on frozen tyres. It is not laboratory data.

If it reads biased on your car, there is a manual correction (up to ±20°) that adds or subtracts for the colour.

DRIVER INPUTS MODE

An alternative layout designed to sit exactly on top of iRacing's own pedal overlay, so everything lines up and reads together.

SETTINGS

  Size            by dragging with the mouse
  Opacity         so it doesn't cover the track
  Tyre correction ±20° if your car reads biased
  Reference       the CSV of the lap used to work out the braking
                  countdown

Everything saves itself next to the program.

IF SOMETHING GOES WRONG

The braking LEDs never light up → the reference lap is missing.

   Without a lap to compare against there is nothing to anticipate: load
   a CSV or record a lap.

The temperatures are all the same or don't move → until you go through

   your pit box once, there is no real measurement to start from. Go
   out, drive and come through the pits: from then on it anchors and
   starts moving.

The temperatures don't match the sim's → they are estimated, see

   above. Use the manual correction if your car reads off.

I can't see it in VR → it has to be in borderless overlay mode to be

   pinned. Otherwise the headset won't grab it.

It's eating my fps → it shouldn't: that's exactly what it was built