Before I go further, here's my setup:
iPhone 4 running iOS 5 (I'm staying away from 6 until absolutely necessary -- possible issue?)
XGPS150, with the upgraded firmware, running at 5Hz
PLX Devices Kiwi2
HLT 17.0.2 Grand Prix Edition
5 GoPro cameras (I don't use the iPhone for video)
Post processing in Race Render 2
The day started out bad, when HLT crashed the first time I started it, and then took several minutes to fix all the databases and sanity check the old lap data (I haven't deleted *anything* from last year, so there's a lot of old data on my phone). Throughout the day, it seemed to switch from forward to reverse video at random, which was pretty annoying. During the track sessions, I kept seeing really strange numbers when I would cross the start finish line, numbers that were clearly NOT my actual lap time. I don't generally look at HLT while I'm on track, though, so I didn't really see a pattern, just observed a few strange numbers. For example, once it showed my lap time as around 30 seconds, and since the track record is in the upper 40s (in a car just a tad more capable than mine
it's pretty obviously bogus. After each session, though, I always check the lap list to get an idea of what times I was running, and when viewed on HLT the times all looked about right. The next day, when I did a sanity check of those times against the times measured in the video, they were within .01 seconds. At the track, my biggest problem was the day/night display switching at random, and a LOT of crashes. About every 3rd time I started HLT, whether to set up for a new track session, or to show off my personal best 1.04:64 lap time to friends, it would go into the "Checking databases...." code. My understanding was that HLT only did this after a crash, otherwise, I don't why it happened some times and not others.
The real headaches started when I exported the data for use in Race Render. First of all, HLT crashes roughly 25% of the time when I try to export, and it does so in different places (sometimes when I select the lap, sometimes when I touch the export button, sometimes during the generation of the data)
I always edit the exported CSV data file to re-index the laps starting at 1, and I happened to notice that the LAST data point for some of the laps had a time value that was several orders of magnitude too large. This would totally throw RR2 off, but the simple workaround was to just delete that offending row. For the 4 sessions I exported, I had at least one such bogus row in all 4 of the files, IIRC. Once I had corrected that glitch, I then found that the actual data was *horrible* quality. My XGPS150 is providing data at 5Hz, and yet when you watch the cute little red dot wander the track map generated by RR2, it looks like I was driving on the hill across the river from the front straight, where the spectators sit. I'm not that bad
In the data file for the first session the accelerometer data just disappears, and those values drop to 0 and stay there. The measured speed is also WAY off -- in some places, it would DROP while I was accelerating, and since I *know* my apex speeds on all 7 corners at LRP, I can see it was off by as much as 20 mph in some places. I will assume that since measured speed is derived from the GPS data, that the root cause here is bad information from the GPS. Whether it's the fault of the XGPS150 or HLT I can't tell, but clearly HLT has other issues as well, since it generates bogus data in the output files. Also, the accelerometer data has nothing to with the GPS (I assume...). FWIW, I have POI Detection set to Wide, too.
The data for the 2nd session seemed a little better, but the GPS was wandering WAY off track again, and this time, it started to miss the start/finish trigger as a result. Several laps were combined in pairs into a single lap, as a result of this. The data for the 3rd and 4th sessions had no merged laps, but the accuracy of the GPS data is still questionable, since the measured speeds are clearly very wrong.
As a result of this, the only data overlay that was worth anything in RR2 was the track map, and only in the sessions where that data wasn't so bad that the track map didn't even resemble Lime Rock Park?
I have uploaded the exported data files, and a sample video file that shows how poor the GPS data is to:
http://ftp.openefs.org/hlt (Abusing the ftp server for one of my open source projects
)Right now, I am *extremely* frustrated with this software, because my track days are precious: I only get on track once or twice a month, and this data is critical for maximizing the learning experience. Last year, I had everything working wonderfully and I have been promoting HLT to other track drivers, but had this been my trial run with the software, I'd almost ask for my money back.
My next track day is May 2nd, and if I have no workarounds or solutions for these problems by then, I'm going to split my 4 track sessions between HLT and the TrackAddictHD product from the Race Render guys, and see if that does any better. Right now, the lack of stability and the data quality are forcing me to look for other options.
Harry -- I am a BIG fan of the work you've done, and I'm not going to give up on HLT just yet, so if there's anything else I can do to help you get to the root cause of these problems, please let me know.
and both should be fixed in 17.0.3
