GPS Limit Timing on iPhone or Android?

[slider2828]

Hey guys, anyone use their phones for Lap Timing?

Trackmaster - Welcome (http://trackmaster.trackaroo.com/welcome)

I found trackmaster on the android and looks like a really sick application.... Any feedback or ideas?

http://www.trackaroo.com/files/gmeter_gal.jpg

http://www.trackaroo.com/files/split_markers_gal.jpg

http://www.trackaroo.com/files/logger_horiz_gal.jpg

[LimeLite Racing]

Damn that looks really sick.

[!Zar!]

That looks pretty sweet. Wish they had it available for the iphone.

[ILoveMyRHS13]

Looks pretty sick.

I've don't know how accurate the GPS is at timing moving targets... I have speedometer apps and they always read at retarded numbers. Maybe this is different, I'll check it out for sure, though.

[orion::S14]

Most the time, the GPS in a phone isn't fast enough to accurately be used as a timer for motorsports.

For example, most phones have what...a 1hz GPS?

Something like a Racelogic 'Performance Box' or VBox (drift box?)...have a 10hz GPS.

So as nice as an 'app' may seem...the hardware is not there to support it.

- Brian

[TheWolf]

the tracklogic one for the iphone looks good and will support a plug in GPS like a tomtom if you want the greater accuracy or it will try to do what it can with the factory one.

[Sam_Well.13]

WHOA. dope. ima have to try this on my wifey HTC EVO

[Sam_Well.13]

6.99 for this app. and these smart phone even has a camber gauge....fawkin crzy!!!!

[slider2828]

Most the time, the GPS in a phone isn't fast enough to accurately be used as a timer for motorsports.

For example, most phones have what...a 1hz GPS?

Something like a Racelogic 'Performance Box' or VBox (drift box?)...have a 10hz GPS.

So as nice as an 'app' may seem...the hardware is not there to support it.

- Brian

Well if it is ball park its good enough... If you were hard core, then you would get something like GPX or something.... But go to app store or market and get GPS Test its free... They have a car speedometer display based on GPS and its pretty damn close when I am on the freeway....

BUt as said before you CAN get extensions into other GPS devices for more accurate results.... By no means am I saying its a replacement for real dataloggers, but I am hoping it gets like 70% of the way.....

[TheWolf]

The Iphone 3g and 3gs use a 1hz gps chip.

The Ipad and 4g use Broadcom BCM4750 which is a 2hz chip.

Vbox mini is a 10hz device. Vbox goes into 10-20-100hz devices.

This all gets into what you really need. Since Orion in on here I'll use a track he drives and datalogs at. Gainesville. If you're running a 1 minute lap there. With vbox mini you're getting 600 points around the track. If you're using your iphone 3g you're getting 60 points. But since you're under 60mph most of the time since it's a tight track, then you might get some useful data but you wont get everything your looking for. With a new iphone 4g. 120points. Alot better and getting into the range of more useful. Laptimes and splits are fine. If you want to see if you braked into the 3rd corner later on lap 1 then lap 3 I don't think you'll have enough data points. Overall G-loads and general data like how much of the car you are using, is the car handling both directions adequately and if one lap was faster than the other and where it was faster could probably be determined at that lower rate. Fine improvements such as cornering entry speed or exit speed could not reliably be determined.

I would not use this for autox unless on a 4g or a external GPS receiver. The refresh rate would show bad and turn slaloms into straight lines track map wise it would be a disaster.

It looks like an awesome tool though for someone who wanted to do HPDE track days or was running a race track at speeds under 120. Get a good solid mount for your phone. That can not be underestimated.


Harry's lap timer pro for iphone works quite well. Dash Command also works if you want an OBD2 scanner + data logger...

[slider2828]

The Iphone 3g and 3gs use a 1hz gps chip.

The Ipad and 4g use Broadcom BCM4750 which is a 2hz chip.

Vbox mini is a 10hz device. Vbox goes into 10-20-100hz devices.

This all gets into what you really need. Since Orion in on here I'll use a track he drives and datalogs at. Gainesville. If you're running a 1 minute lap there. With vbox mini you're getting 600 points around the track. If you're using your iphone 3g you're getting 60 points. But since you're under 60mph most of the time since it's a tight track, then you might get some useful data but you wont get everything your looking for. With a new iphone 4g. 120points. Alot better and getting into the range of more useful. Laptimes and splits are fine. If you want to see if you braked into the 3rd corner later on lap 1 then lap 3 I don't think you'll have enough data points. Overall G-loads and general data like how much of the car you are using, is the car handling both directions adequately and if one lap was faster than the other and where it was faster could probably be determined at that lower rate. Fine improvements such as cornering entry speed or exit speed could not reliably be determined.

I would not use this for autox unless on a 4g or a external GPS receiver. The refresh rate would show bad and turn slaloms into straight lines track map wise it would be a disaster.

It looks like an awesome tool though for someone who wanted to do HPDE track days or was running a race track at speeds under 120. Get a good solid mount for your phone. That can not be underestimated.


Harry's lap timer pro for iphone works quite well. Dash Command also works if you want an OBD2 scanner + data logger...

yeah the android I am using (ATT Captivate) has the BCM4751 chipset, smaller, but I its using the same chip design as the 750 except its 65nm.... so I think I should be good using this software.....