WifiLapper - Laptimer, Data Logger, Telemetry Transmitter - Now Free (Page 1 of 4)

Awesome!

I'll going to try and implement this alongside my video streaming. Would be very cool to have telemetry data with the video.

ah, missunderstood. Still cool though. I'll probably still try and get it working.

I'm in the process of trying to get a boosted router setup working so that i can maintain a wifi link from car to pits. Pretty sure i can make it work.

Cool. I'm trying to have the router in the car, and the receive antenna in the pits. I do think i can get enough signal boost to cover the range of NHMS. I know my cell phone doesn't have the wifi range needed, so i'll have it go through the router to get to the pits.

I'll stop cluttering this threat with my router talk though, i've been covering it in the live video threat in the photo/video section.

The app looks awesome though, and i'll probably be using it come october.

Since it uses the wifi router to do data transmission, coverage shouldn't be an issue.  You just need the router, phone, and laptop.

I don't currently have plans to do an iVersion - I don't have objective-C skills, a mac, or an apple developer account.  And now that I have no future revenue prospects, making those capital investments isn't looking attractive.  I may open-source it if I get the time and git skills, then someone could cough up a port.

And although they're just optional features, the iPhone's method of interfacing with stuff like external OBD2, GPS, and analog inputs is either different or nonexistent, so a port would be noticeably worse than the android version.

This sounds fantastic.

If we choose not to set up the router, will the phone just log data to the SD card all day, and we can download it later?

LeMons-inspired technology development. We're like NASA (the space guys)!

The phone I use is a $100 motorola droid I got off amazon.  Unlocked, no data (or voice or text) plan, has been tested in a race car, slide-out keyboard, no phone plan, the GPS works, it's fantastic (albeit a bit old).
Link: Amazon

The only other problem other than the oldness is it bugs me to sign up with Verizon whenever I completely power it off and on again.  But it's a single button-press to exit that screen.

You could always pick up an IOIO and manually wire in sensors for pre-OBD2 cars.  I've tested the IOIO stuff, but I'm so hurting with electricity that I broke my board about a week after getting it.  Other people in the "open-source data" thread were thinking getting an arduino, hooking up car sensors, and emulating a bluetooth OBD2 reader and connecting that way.

The stock GPS on almost all phones is 1hz, and the accuracy (at least for my motorola) is pretty solid.  You can tell what side of the track you're on.  For maximum laptiming accuracy, you'll want to put your start/finish line where your car isn't accelerating quickly, so at the end of a straight before the braking zone is best.

You can see the smoothness of a 1hz trace in this old summary page from when I was testing it on my bike:

I'd accept $20 for this app
I may make a "donate" version that'll be identical except for costing $5 in case people want to throw me some beer money.

The QStarz unit is a bit annoying - by default, it doesn't send all the GPS data I need (it's missing velocity) - you need to download GPSView from the QStarz site and configure it to send the VTG info.  I made a how-to for that here: https://sites.google.com/site/wifilappe … tarz-setup

Yep - start a race, track walk while tapping for your splits and start/finish, then end the race (menu->quit or the back button).

Next morning, go to the load-race screen and long-press the race you created (it'll have a track map icon, which I think looks pretty swell).  Choose "resume".  Or if it's a multi-race format, you can choose "new race, same splits".  It'll even remember your best lap from the previous session so your ringer driver's prestige can carry over day to day.

Another thing to mention - for those guys who want to try it out, if you enter test mode (options menu), it'll do 20-second fake laps and give you an idea of how it operates without you having to do sketchy laps of your neighbourhood.  I have scared many a neighbourhood kid on my bike as I did testing laps: "hey mister, why do you keep coming by?"  "for science!"

Correct.  Don't forget a real mount for the phone.  It's difficult to macguyver up a mount that is safe for your phone and still visible to the driver.  In a pinch, a team ran my phone with zipties and double-sided tape, but it's better to have a $20 mount setup: part 1/part 2

I use this $100 phone for development, and it has been raced: link.  It bugs you to activate with Verizon, but that's fully ignorable by clicking the back button when the screen comes up.  The GPS (1hz) works, and the bluetooth has worked with the expansions (OBD2/10hz GPS) I support.

Warning on phones: Some phones are locked so you can't use GPS unless it has a data plan.  If you go buy one off craigslist (a mostly-fine method of getting one), make sure you test GPS first before you hand over cash.  I actually started developing this laptiming code in fall 2010, but I got a test phone locked to our local evil carrier, and didn't feel like dropping another couple hundred bucks to get one that worked, so stuff was delayed for a year until my chumpcar-racing friend got a phone with working GPS and I could do some testing.  The motorola I linked above has working GPS without a data plan.

Edit: It's too bad  for this weekend that 1930s-era aircraft engines don't have OBD2...