[downtowndeco]

I'm using an infared light bridge & a printer port. I've tried messing w/the settings a bit but am still missing laps. Various cars, various lanes. I can find no specific reason. Thoughts? thanks.

 

[RichD]

Are you using a common ground for all of the lanes? That is known to cause problems. It is safer to run seperate grounds for each lane. Poor emitter to sensor alignment could be a problem, especially if the sensors are recessed a bit. Dust can get into a recess and block the light. If nothing else works you might switch to a serial port setup.

 

[AndySlots]

In one of the setting boxes, there is a tick box for TrackMate compatibility. Clicking, or clearing this used to sort my problems out.
You can also check the IR downlights using a Digital camera or similar. You will not see much light, but you will get an indication that they are on or off. If you are running under certain lights or sunlight, this can trigger sensors, or prevent them from working. Make a shade/ tunnel over the sensors and light bridge.
Also, check the debounce is not set too high.

andy

 

[downtowndeco]

I might be on to something. I ran 8 five minute races (me vs rubber band racer). When I made a concious effort to not run any closer than a couple feet from the other car at the start/finish I did not lose any more than one lap, and in most cases the number was zero. I have a sneaking suspicion I may have miscounted and so there may have not been any laps lost.

But when I ran a race & tried to cross the start/finish at the same instant as the other car, the lap loss was anywhere from 4 to 7 laps. Usually it was the faster car (me) that lost a lap. I traded lanes back and forth w/robo racer and there did not seem to be a difference which car it was or which lane it was in.

The good news is there seems to be some correlation between crossing the start finish at the same time as other cars and losing laps. The bad news is I'm not exactly sure what to do next. Will dicker with the settings a bit more.

Basically it seems that if two cars cross at once someone may lose a lap. That is the key.

 

[downtowndeco]

Still having problems.

I changed from infrared to incandecent bulbs & am still having the same issue. Sometimes when two cars pass over the sensors about the same time one may miss a lap. Then two laps later the lane that missed the lap records a "double" time. In other words, the average lap around my layout is 4.5. What it will do is one lane will miss a lap & then 2 laps later it will record a 9 second lap time.

I've tried messing w/the debounce & the setting to account for faster/slower computers. Anyone else ever have this problem? Thoughts?

 

[munter]

QUOTE Dust can get into a recess and block the light. this has been the only problem I have had with laptimer2k.

How deep do you have the track sensors? Are they in the bottom of the slot or mounted beside it?

 

[downtowndeco]

Beside it. I don't think it's the sensors because this only seems to happen when two cars pass the s/f at the same time. Any other time it does not miss laps.

QUOTE (munter @ 22 Aug 2011, 08:45) <{POST_SNAPBACK}>this has been the only problem I have had with laptimer2k.

How deep do you have the track sensors? Are they in the bottom of the slot or mounted beside it?

 

[RichD]

You need to find out if this is a hardware or a software problem. A count either gets triggered by an open or closed circuit no matter what kind of sensors you use. If you disconnect the sensors and just touch the wires together you can duplicate the situation when two cars cross at once. If you do two sets of wires at once and the count is OK then your problem must be with the sensors. If you get the miscount the problem is with the cable, the computer port or the software. You never did say if you checked for a common ground wire, that is a known issue with systems of this sort.

 

[downtowndeco]

Common ground? I use two AFX wallwarts. Are you saying one should be plugged into one outlet and the other in a seperate one? Thanks Rich.

 

[PJF]

QUOTE (downtowndeco @ 22 Aug 2011, 17:51) <{POST_SNAPBACK}>Common ground? I use two AFX wallwarts. Are you saying one should be plugged into one outlet and the other in a separate one? Thanks Rich.

No mate, not on the main power side.

Do the sensors have one cable coming from the ground pin on the port, then going to all four sensors. If yes then I think that may be the problem.

I use the same system on my home & club tracks, on both systems I have ran separate ground cables to each switch along with the return switch cable. I have had no problems with missing laps, ever. The only problem I have come across is a long timed race finishing early

.

Basically you need parallel cables to each sensor/switch.

I hope this helps ?

Paul.

 

[downtowndeco]

Last night I tested the counter using a sheet of cardstock instead of cars. I tried testing it 2 lanes at a time & 4 lanes at a time by quickly sliding the card over the sensors. Even though in most cases the times were all identical (all four lanes reading 4.650 for example) I did not lose any laps. I did five 5 minute "races" and missed no laps. I then tried sliding the card at a slight angle so that I would get a slight variation between lanes, still, no lost laps.

Huh. What does that mean? I have been testing using Mega G's. Is there some weird electro/magnet thing that happens sometimes when two cars pass over the sensors at about the same time? Do the cars go over the sensors too fast? I'll try some slower cars today but it's a little harder for me to test because my SRT's are no mag which means I can't set one as a rubber band racer because it won't stay on the track. Understand, I don't have a racer that can just run over to help me test any old time.

 

[PJF]

Got me stuck mate.

I use only micro switches & I can run four cars over them at the same time with no problems, so its looking more like the issue is with your sensors & not the software. I will see what settings I have at the club track tonight & let you know.

Paul.