Hi all
As you have seen we are struggeling a great deal with our phidget/PCL setup, and apparently for good reason.
I finally received reply from phidget with regards to our missed lap counts. The reason for this problem lies within the phidget card, which only refreshed 125 times pr sec or roughly every 8/1000 of a second.
Since our sensors (slot based detectors) are only triggered for 3/1000 of a second when running at normal pace - Phidget is not able to see the input. We are now working on a electronic solution which will eliminate this problem by using capacitators - but still this most certainly an emergency solution...
It is interesting when you considder that phidget uses this much time on obtaining input which makes timing with 1/1000 sec precision impossible - actually we are looking at close to 1/100 sec precision. Of course PCL will show/calculate time on 1/1000 sec intervals, but since the program will only receive input from phidget every 8/1000 sec, this is more fiction that reality.
Hope this information can be usefull for people currently considdering to build lapcounter hardware - if you use phidget you must use either a light bridge (as sold from mainline hobbies) or use deadstrip - otherwise the detection is not going to work.
Once we have completed the final print to solve the matter I will post pictures of our hardware including sensors - it is a GREAT way to detect cars, but unfortunately also very demanding on hardware
:-)
Will keep you posted - any comments appreciated