iPhone as laptimer--good enough?
 

Over the weekend at Mid-OH, between the rain drops, a driver in the next garage was using his iPhone with Harry's lap timer app to video the runs. With the app, it provides lap video, timing, a track map and indicated corner forces. you can also add a obd connection to pull in engine speed and other stuff tot he overlay.

From his iPhone the video looked great, but when I looked at a few other videos on the web,using the same app, the video looked a bit jerky or wavy to the point of being distracting.

I'd appreciate views of people that have used their smartphone as a laptimer regarding the quality of the video, accuracy of the timing and the details of their individual setup.
thanks for any help.

Mike,

iPhone as lap timer is good enough if you get the TomTom GPS mount
I prefer MaxQData (CMS) over Harry's lap timer as it gives you predictive lap timing
But if you want HD video, like this: Boxster vs Shelby Cobra, Audi R8, Lamborghini Superleggera - YouTube
you'll need an HD camera like the GoPro I am using

Looks good Chris--what all do you have for a setup?
How do you overlay the data onto the video?

I agree with the video quality--GoPro vs. iPhone--so I'm thinking GoPro for the video and just try to figure out how to get the data on top of the video; nothing exotic just speed and lap time to begin. Have you tapped into the OBD?

detailed writeup can be found here:
Porsche Club of America Golden Gate Region • View topic - experience with GPS based lap timer system

a few errata to my writeup (please read the writeup first)
The 10 Hz GPS I intially used died and I replaced it with a - cheaper - 5 Hz unit which does the job just as well
The company (MaxQData) which made the PocketPC version then also created an iPhone version but then went out of business
I have their iPhone product and Harry's lap timer both installed on my iPhone and very much prefer their product, reasons being:
* faster, more accurate sampling points
* supports landscape mode
* predictive lap timing
Apparently CMS has taken over the product but in all fairness I never tried their version
Any GPS lap timing on the iPhone is limited by the fact that the sampling rate of the "location service" is limited to 1 Hz no matter how fast the GPS is that you have connected

I have added two pics which show my setup
The mount is a GoPro mount which I had laying around and you can see the GPS module sitting on top facing towards the sky

Thanks again Chris--more questions:

-Dell Axim(?) PDA? I take it it's purpose is to display the lap time and save the info?

-Unless I missed it, how are you overlaying your video from the GoPro with the data from the Axim?

thanks, Mike

Yep it does both records the laps and displays the laps live
The overlay is described at the end of the link I posted above