TrackMaster Lap Timer Android App

[MadMel]

I took up riding track days about a year ago, and have been working on improving my skills. Part of that improvement is knowing if I actually am getting faster, and if so, why?

Enter TrackMaster. This little Android app uses GPS to log your laps. Not just lap times, but your position and speed at all times while you're riding. This lets you compare across laps... for example, you might try a different line through a turn, and then see how that affected your exit speed.

You split your track into sections, using split markers. The app will show you your times and speeds for each section of each lap, and produce a theoretical best lap time (i.e. if you rode a lap where you hit your best time for each section, your best time would be X).

The interface for viewing your laps uses a Google Maps backdrop, and displays your line with green when you are accelerating, and red when decelerating. You can click any point on the map to see your speed and elapsed time to that point.

And the beauty of it all is that you can look at all this trackside, between sessions.

The data is synced to the TrackMaster website for storage and sharing. I took these screenshots from my Android tablet. The data syncs from my phone to the web, and then down to my tablet.

TrackMaster does a nice job of interpolating lap times between GPS points, so if will best-guess the exact millisecond that you crossed the finish line based on the GPS readings before and after the finish line. The in-built GPS of phones takes readings at 1Hz (once per second). This is a little low for really accurate lap times, and really accurate arcs through tight corners. TrackMaster lets you tie a bluetooth GPS to your phone. The external GPS will be more accurate than your phone's GPS, and will take readings at 5Hz or 10Hz (5 or 10 times per second). My phone is old and slow, so I have my GPS set to 5Hz, so it won't have any issues keeping up.

My GPS is a QStarz BT818XT, which has a switch to read at 1Hz or 10Hz. I reconfigured it using the software to read at 5Hz instead of 1Hz.

Costs: TrackMaster is $6 from the Google Play store. You be lappin', mon. You wanna get all hardcore and buy an external GPS? Mine was something like $80. The TrackMaster add-on to use Bluetooth GPS is $4.

For mounting on a Daytona, I put my phone into a little neoprene camera case, and stick it into the cubbyhole under the seat. You could stick into a pocket or something if you wanted, gotta love Bluetooth. I have the GPS velcro-mounted in the tail section, on the plastic bit where the "tool kit" (read: screwdriver) was until you bought the bike, saw it, laughed, and threw it in the trash. GPS Pro-Tip: a decent GPS does not need to be exposed to the sky, it just shouldn't have steel between it and the sky. A thin bit of plastic or fibreglass is no problem. Keep in mind that if you don't use a Bluetooth GPS, your phone will have to be mounted where it gets a decent GPS signal. The GPS battery easily lasts a day, probably a weekend, so turning it on and putting the tail section over it doesn't pose any inconvenience.

Issues: I've only found one issue: the synchronisation to the web can be flaky, and I actually lost some data once. There is an easy solution: back up your session at the end of the day.

That's about it. Got ?'s, I'll try to answer.

[whirlybird]

That is awesome. I am going to the track tomorrow and I do not have a lap timer. This might be just the ticket. So does it do actual lap times or just "theoretical best lap" times?

[MadMel]

Originally Posted by whirlybird

So does it do actual lap times or just "theoretical best lap" times?

Both.

[drsubie]

awesome sounding app, will have to try it out!

[Knolly]

I've been using Trackmaster for my last few track days and love it.

Where did you buy your BT GPS? I've been meaning to snag one myself.

[Willy Wonka]

If you have a Nokia phone (symbian) I can recommend RaceChronos (free). I use it with a Qstarz BT GPS device. Its very accurate and you can export the data to google maps etc.

[MadMel]

Originally Posted by Knolly

I've been using Trackmaster for my last few track days and love it.

Where did you buy your BT GPS? I've been meaning to snag one myself.

EBay. Mine doesn't have any data logging capability, but that's ok since the data is logged on your phone.

I'll post up some tips on optimising the GPS' internal configuration for use with TrackMaster.

Also, I did put the GPS under the seat once, and it worked. But I prefer having it mounted somewhere with a less obstructed view of the sky. One could mount it on the instrument panel below the windscreen or the headstock, rather than in the tail section like I did. If you have a street tail section, it is only one screw to get at.

[MadMel]

Here are a couple of things you can do to configure your QStarz GPS to provide best performance with TrackMaster. My GPS is a BT818XT, but these may apply to other QStarz GPS'es as well.

To do these things, you need to use some QStarz software.

1. Download GPS View and unzip it to a folder on your computer.
2. Plug your GPS into your PC, and turn it on.
3. Look at Device Manager, and note which COM Port your GPS is using.
4. Start GPS View, and on the Status tab, set the COM Port and click On.

A note on GPS measurement frequency: Hz is the measurement of how often a reading is taken by the GPS and provided to your phone, in times per second (i.e. 1Hz is once per second, 10Hz is ten times a second).

Only Send Required Data From GPS To Phone
A GPS provides data to devices using a standardised data format (called NMEA 0183). This standardised format allows an application like TrackMaster to work with a variety of GPS'es without specifically knowing exactly which GPS you have. To meet the standard, a GPS provides a bunch of data to the device (i.e. your phone), because it doesn't know exactly what parts of the data you need.

TrackMaster only uses some of the data provided by the GPS. It has to filter through the rest of the data and discard it. This takes processing power, slowing your phone down and draining the battery. You can set your GPS to only send the data that is actually used by TrackMaster. This may be the difference between your phone being able to log GPS readings at 10Hz instead of 5Hz, or 5Hz instead of 1Hz.

To configure your GPS to only send the necessary data:

1. Go to Setup > NMEA Output Settings, and you'll see a bunch of 3-letter data types listed. TrackMaster only uses the RMC and GGA data types.
2. Set RMC and GGA to 1.
3. Change all other data types to 0.
4. Click Confirm.

Set the Frequency of GPS Readings Provided to Your Phone
More GPS measurements per second will result in more accurate lap times and a more accurate display of the line you rode, but the tradeoff is more data for your phone to process, store, and sync to MyTrackMaster.com. At 10Hz, some phones may not be able to keep up with the readings from the GPS. TrackMaster interpolates the time when you crossed start/finish or a split marker from the GPS readings on either side of it, so a 10Hz frequency isn't twice as accurate as a 5Hz frequency.

The GPS in your phone reads at 1Hz, which is a little low for accurate lap times and displaying your line through corners accurately. Personally, I think 5Hz is a good balance between accuracy and data volume.

My GPS has a switch on the side, which lets you choose 1Hz or 10Hz. I reconfigured the GPS to provide data at 5Hz when the switch is on the 1Hz setting. To do this:

1. Make sure your GPS has the switch on the 1Hz setting
2. Go to Setup > Fix Update Rate
3. Click Query to confirm that it is on the 1Hz setting
4. Change the update rate to 5Hz, and click Set.

Regardless of whether you do this procedure or not, it is important to tell TrackMaster what rate your GPS is providing data at. In TrackMaster, under Settings > GPS > Set Rate, change the rate to your rate.

DGPS
If you have WAAS in your area (and in the continental USA, you probably do), you may be able to achieve more precise ground locations by turning Setup > DGPS > SBAS on. A Differential GPS uses permanently-mounted GPS'es on precisely known locations to correct errors in the locations provided by satellite signals. If you want to learn more about it, Wikipedia is your friend.

[whirlybird]

I got to looking at my info for the 4 laps that it was working before the battery died and it didn't seem very accurate. The overlay of the google maps track map and the gps's account of where I had been weren't even close to lining up. It showed me way off the track in the dirt. Did I miss something for configuration or what?

[MadMel]

Originally Posted by whirlybird

I got to looking at my info for the 4 laps that it was working before the battery died and it didn't seem very accurate. The overlay of the google maps track map and the gps's account of where I had been weren't even close to lining up. It showed me way off the track in the dirt. Did I miss something for configuration or what?

Could be a few things that I can think of. Might be that your phone's GPS isn't very accurate. Could be that where you mounted the phone didn't have a clear enough view of the sky, so there was multipathing (the GPS signal you were getting was bouncing off something before it got to you). And lastly (and entirely possibly) - Google Maps' imagery isn't georeferenced properly - it's actually off and your lines are correct, but Google Maps is misplaced underneath them. If your lines look correct, just generally shifted in one direction, it's probably the latter. If the lines look correct at times, but are sometimes out of whack, it's probably one of the first two.

I haven't tried it with just my phone's GPS, so I can't really comment on what the results look like from it.