RRW did an article on one last year. Can't remember what it was called though. Track master or something like that.
I'm gonna download it now and try it out tomorrow. Anyone use this without the external gps. I have an htc evo, wondering how accurate it will be. I'm gonna compare it with my xt mini.
Tried it out in my work truck when I first got it. Did a couple laps around the neighborhood. Worked fine enough to get an idea of what was going on. I liked that I could sync the external gps which was safetywired to the bike, set the phone to go, toss the phone in my leathers and go. The twitter feature is nice. The GF could see my laptimes as I made them. Though, it does FLOOD your twitter account. I know you can save them to excel so you should be able to print them and keep them with the rest of your logs.
Tried Trackmaster at Barber a couple of weeks ago. Not reliable without external gps. Must not update fast enough with only my droidX2. If it works with the external it would be useful. It took me a while to figure it out-it isn't just turn on and go. Someone told me it was easier if you downloaded and printed the directions instead of looking back and forth on the smartphone. It's probably worth the $10, but it's not the berries either. If you don't like it they offer a refund I think.
iPhone and droid only have 1Hz refresh rates on the GPS (ie 1 plot per second). I've used an external Bluetooth GPS receiver set to 5Hz refresh with Racechrono and it works much better.
How accurate is the 1Hz internal GPS setup? Is the 1Hz still reasonably accurate if not as detailed as the 5Hz external GPS setup? My HTC droid eris will not recognize external GPS units.
It'll interpolate the laptime based on the weighted distance between the two sample points bracketing the start/finish line, and give you an answer to 3 decimal places. It should correlate well to a beacon-type timer, even at 1Hz. 5Hz lets you trace your position and acceleration much better. 10Hz may be overkill.
the 10hz remote gps units are available for about $80 and they are providing 10 position updates per second. Wouldn't that be the way to go if you really want to see exactly what you are doing through each corner ?
10Hz means 10 times-per-second... It's a lot of data, and the files grow quickly. Plus there's some inherent inaccuracy in each measurement, but as a whole, it'd show you a precise (not-fuzzy) line that's very slightly 'off' of your true line. Your position would become a fuzzy (imprecise) dot if you recorded long-enough while sitting still, but since you're moving, the error in the line is small. The extra data isn't all that helpful beyond the 5Hz point. To get REALLY useful data analysis, I throw the raw data into Excel, and then do 'stuff'. 10Hz for a 120s lap is 1200 points... Buy the 10Hz unit, and set it to 5Hz. It's hard to find 5Hz units anymore, just as it's hard to find the BT-only receivers anymore (they're all 10Hz traceloggers, seemingly).
I've used these with Chris Peris and they worked really well..... http://protrackguides.com/data-loggers/
I have the same phone but that doesn't matter. Unless you mount it on the tank/bars I don't think you'll get the best readings. The thing nice about the BT key fob type GPS antenna is that you could put the phone in your inside chest pocket and it should communicate without any problems. By the time I got my set up I haven't been back to the track.
