Dash 3 lap marker problems

[gavinp]

I have noticed that the Dash 3 seems to be pretty inconsistent detecting that you've ended a lap, having set a start/finsih marker using a Dash 3 button.

It appears it is very sensitive to lateral track position. EG, if you set the marker when you are on the right side of the track (let's say in a warm up session, staying off the racing line), when you later pass the same point but on the other side of the track (say, on the racing line) the marker is missed, resulting in a very long lap time next time around!

Anything that can be done?

I found a temporary fix is to set the marker at the turn in to a bend, because you'll probably always be at the same point on the track each time around.

g

[osborni]

You can define the lap and sector markers in software and load up a .LAP file on DL1 startup. Make the lap markers really wide so there are no errors. GPS drift is part of the problem, but placing manual markers in software will compensate.

[gavinp]

Still having issues here.

I set the marker manually in software yesterday at Brands. At this circuit some of the track in different directions is close, but I presume however wide you create the marker the direction arrow on a marker means it still works even if it extends over a second bit of track?

Also, do the .LAP files need to be called MARKER01.LAP or can they be BRANDSGP.LAP and still work?

What are the units (m) used to set marker width, meters?

So, even if all the above works (calling it BRANDSGP.LAP, 200m setting for width, selection one as a start finish) the Dash 3 was still not getting the start marker every lap! The track is certainly less than 200meters in width!

I also made sure there was a GPS lock before starting off. For information, I turn the whole system off after each run, so I leave the .LAP file on the CF card and I presume the Dash 3 just loads the file ech time it powers up.

Any thoughts?

[Support]

The width of the track marker makes no difference to the DASH3, this is purely used in the Analysis software. The direction is important. The system is looking for the passing of the lap marker in a similar direction at a similar point, a change of 10m shouldn’t make a big difference, from memory the actual width of marker used is around 50m. In terms of accuracy it is certainly best to try to add the markers in the same position as they will be used.

The lap marker file can be labeled any valid 8 character name then .lap. As stated, you do need to have a valid GPS lock before you start logging.

Please let me know which version of the DL1 firmware you have, this can be found by loading in a run file and looking in the run manager for the run information. If in any doubt, send the file through to Martin Hill so he can take a look at it, mhill at race-technology.com

[gavinp]

Hi. Firmware version 13-1. Logger serial number 254 (an early customer!).

And to be specific, some laps were shown fine (eg 1min 47secs) say for one or two laps, then it would miss the markers for about 4 laps (and show a time of about 7 mins or thereabouts), then it would start working again and show a lap of 1min 47 secs again. My driving is pretty consistent around Brands GP, so typically no more than a few feet from the same line each time.

I am switching on engine, then logger with CF card in with .LAP file (just one) on it, then switch the dash 3 on, once that has initialised I then start logging.

g

[Support]

What could possibly the problem is an issue with the distance from where the marker is to where the marker crossing is detected on the DL1. To get this as good as possible it is important that the marker is added on the racing line. If the marker is added from the Analysis software then it is important that the centre of the marker is where the track is, and that the marker is added at 90 degrees to the track.

If you have a .run file and a .lap file which was causing problems could you please send it to me gummi at race-technology.com with reference to this thread.

[emersom]

Did this ever get sorted?

[924RACR]

I suspect it is still, well, maybe not a "problem" as a sensitive area.

I was at VIR this summer, and remember setting a start/finish marker in the pits, fully past the right of the track, and not picking that up the next lap when we passed by on the line, fully on the left of the track.

...and that's a pretty narrow track.

Edit to update: after observing this, I re-made a .lap file with the start/finish added using the analysis software; this .lap file worked great without issue, and I was able to pick up that lap marker on future sessions, including from the pits when heading out on track.