Smartphones as data loggers...

[rw99]

I'm duplicating one of my old (Oct. 2011) posts from "the other site", hoping to get some of you to chime in with your current data and video capture setups... the embedded video below plays smoothly when launched directly from YouTube, if you'd like to see the best quality playback...
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So I was on the track the other day, driving at speed & using my phone... ...for telemetry. Hah!



As I become even more track-obsessed, the data hound in me wants to crunch numbers and identify my weak points. There are many, but that also means that there are better times ahead with planning and practice. I don't want to drop money (that I'll need for tires & brakes) on a dedicated datalogging setup ($500 and up, way up), so I decided to try utilizing my Droid X and an app called TrackMaster as the logger. My P-car instructor buddy Glynn is going through the same process with his iPhone and the Harry's Lap Timer app.

Data acquisition by a smartphone's native GPS is limiting if you're traveling at speed. Present internal GPS systems update at 1 Hz (once a second) and have marginal accuracy. So my first step was to buy an external bluetooth GPS unit (QStarz BT 818XT $70) and pair it to the Droid. This GPS can be mounted remotely in the car, and is capable of 5 and 10 Hz rates. The Droid accepted the 10 Hz feed with no problem, so that's what I've been using. Trackmaster logs lateral and longitudinal Gs by reading the phone's accelerometers, so that's incorporated into the data file as well.

I love my GoPro, and the whole point of this exercise was to overlay the data onto the captured HD video. I purchased DashWare (~$40) for my PC; this program very nicely allows you to marry the video file with whatever data files you can collect... selecting and modifying/creating gauges and displays that will then be rendered onto your video file. Very slick program, with a nice synch utility to get everything stitched together correctly in time. Also allows setting splits on your GPS track map, with results graphing.

Next up, I need to find a cheap standalone OBDII logger, so that I'll be able to log RPM, etc. Then I'll be able to add the tach, throttle, and brake gauges and call it complete.

I've also been using a PLX Kiwi bluetooth OBDII dongle, with the Torque app. Lots of useful stuff there, from checking/clearing codes to datalogging and performance meter widgets. The outcome of all this techno toy use has been a real appreciation for the abilities of the current generation of smartphones. When next I upgrade, I'm keeping the old phone as a VERY useful automotive tool.

***EDIT: two years have passed, and I still use my old Droid X for logging... even though it's no longer my phone.


Rich

[virginiavenom]

very cool stuff. need to do something like this. I wonder if the AEM infinity will datalog to a phone?

[Leslie]

My Viper track buddies use their smartphones and Harry's lap timer, showing track, entrance/exit speeds, g force, etc.

They use the go pro's too.

[rw99]

I'll add a reference to an online data analysis tool under development by a good friend of mine that's also a track and data nut: it's called Lapwise, and it's free (OK with you, Moderators?). This is the next step: using those data logs to identify the areas of the track that you need to work on most. Cool stuff.

Check it out at www.lapwise.com


Rich

[FrgMstr]

I use this Bluetooth OBDII jack with Torque. Works well, out of the way of that clutching shinbone, and is inexpensive.

http://www.amazon.com/gp/product/B00...g=hardfocom-20

[Leslie]

I'll add a reference to an online data analysis tool under development by a good friend of mine that's also a track and data nut: it's called Lapwise, and it's free (OK with you, Moderators?). This is the next step: using those data logs to identify the areas of the track that you need to work on most. Cool stuff.

Check it out at www.lapwise.com


Rich

hey Rich, that's kewl, gotta check that out!

I could use it in my Viper, then in student's cars when I instruct...?

[rw99]

Leslie, that's what it's built to do. Most of us that track the car occasionally never get the seat time to really improve our skill set... Lapwise allows a driver to inspect their last session and break down areas of the track where consistency is most lacking. And to go out in the next session to work on those points. I think it can provide an instructor with a very useful tool to put hard data to the points they've been teaching. Poor exit speeds, especially! (Dear Seca T11: I hate you.)

Since I don't track my car nearly as much as I'd like, it's very useful to be able to distill a session or two into really concentrating on my "problem" turns -- especially when HPDE traffic can obscure total lap times. How many truly open laps does one get in a 25-minute session? Never enough.

We've been talking about the ability to integrate Lapwise with video to help users more easily identify track sections where traffic impacts line and/or elapsed time, allowing segment removal and improving the data quality.


Rich