Harry's GPS Suite Forum

Bobl36 wrote:Harry, I have a hard time understanding some of the analytic charts and displays. I am not sure how to read them and how to apply the interpretation to my driving. Is there other documentation that I may have missed in the main on-line guide?

Also, I seem to be missing a step in Autocross set up. everyone tells me it easy, but I often losee data, sometimes it will record and not others...Obviously the problem is on my end in set up. i did see a set up process in this forum dated June 1, 2011...it seems to be different than what is available now. Has anyone done an up date for us non-computer literate types?

Please check the Train the Trainer document available from www.gps-laptimer.de/documentation. It describes some of the charts and gives hints how to interpret them.

For AX just some hints: 1) Make sure you have perfect GPS reception. Add an external GPS if possible. AXes are tight and mostly show extreme direction changes - a 5 or 10 Hz GPS adds a lot of benefit here. 2) In case you get "wrong triggering", add a driving direction to your triggers once created using the AX Assistant. Driving directions are 90 for East, 180 for South etc. Use 1 instead of 0 for North (0 is interpreted as "no specific direction". There is no need to make this too precise +- 10 degree is fine.

- Harry

Bob136,

IMO, an external 5Hz GPS is the minimum requirement for autocross. The internal GPS is not adequate.

You can test the course setup during a walk through. Go to Expert Settings at the bottom of the Settings menu. Scroll down to the Trigger Detection section and touch the button for Allow Low Speeds. You should see green when it's on. Set the start and finish lines with directions and go to Timer mode. Start walking the course. The timer should start at the starting line and stop at the finish line. If you're using the standing start feature, go to the start line, touch 'staged' and then move the phone rapidly forward to start the timer. Go to Analysis then Lap List and select the Track set by touching the User Track Set line. Scroll to the bottom and touch Test. That will show a map of the course with the start, finish and any splits you have created. Make sure the POI lines are perpendicular to the course map with the red direction icon pointing in the correct direction. If the course loops back on itself, you may need to reduce the corridor widths to the minimum of 5m to avoid false trips. That's also in the Trigger Detection section of Expert Settings.

For AX, how about the ability to set the finish first, then the start?

Why? Because if I try to set the start, then walk the course, and finally set the finish it usually doesn't work (too much time, the phone goes to sleep?). So now I am at the finish and with v19 I have to walk to the start, set the start, walk back to the finish, set the finish.

Perhaps this is user error, but a better way to diagnose why iOS MultiCam sometimes doesn't work between devices (in this case HLT on an iPhone 6 and MultiCam on a 4s, all on the same iOS version).

And finally, my favorite request, add the ability to start a lap at the top of the next minute for open road races and rallies.

devenh wrote:For AX, how about the ability to set the finish first, then the start?

Why? Because if I try to set the start, then walk the course, and finally set the finish it usually doesn't work (too much time, the phone goes to sleep?). So now I am at the finish and with v19 I have to walk to the start, set the start, walk back to the finish, set the finish.

You know, you don't have to use the AX wizard to set POI's. You can do it in GPS mode. The other thing you can do is to set the start, walk a little ways and set the finish. Then when you get to the actual finish, you can adjust the coordinates. Or, you can set the finish as the start and vice versa and then edit them.

External Cam Only Mode is my top priority. My iPhone 6s Plus video shakes so badly I need to use something else.

alasorte1 wrote:External Cam Only Mode is my top priority. My iPhone 6s Plus video shakes so badly I need to use something else.

I think I may have to second this.


Also I would like to see more overlay options and more lap analyse options. It would be great if we could import the data into a program on the PC to see in big screen what's going on such as braking points, acceleration points and to be able to see our lines around the track. Not sure if using the Duel 10hz GPS would make it possible to see close to exact line around the track, how close to the corners we come, etc.

With my Qstarz timer I am able to do that and it doesn't hook to the OBD so I am guess it relies on GPS and g forces to show the line and braking/acceleration points.

Maybe more options for what is pulled from the OBD? Not sure if oil pressure and boost is possible.

Different layouts, or customization layouts for the timing screen. I do like the green/red line that changes when you are faster or slower but maybe we can customize how it or even have the whole screen flash red or green for a couple of seconds

BTW, the app is great and even if it stayed the way it is now it is a great tool. So these are just suggestions on my part.

EvolutionX,

It would be great if we could import the data into a program on the PC to see in big screen what's going on such as braking points, acceleration points and to be able to see our lines around the track.

You can. The export data function allows you to export lap or session data in a variety of formats. The two of most interest for your purpose would be .csv for importing into a spreadsheet and .vbo for importing into the free analysis program Circuit Tools. Importing non-VBOX video into Circuit Tools is non-trivial, but everything else works.

I'm not overly fond of Circuit Tools because it throws out the measured speed and acceleration data and recalculates it from GPS fixes. That's particularly bad for acceleration, even if you have a 20Hz GPS, as the double differentiation required for calculating acceleration from a position time series adds a lot of noise, which then requires a lot of filtering which, in turn, can result in significant distortion of the data. That's why I use a spreadsheet instead.

I don't think the ~2m minimum error on GPS data allows you to compare lines with sufficient precision to be of any value. For that, you would need to spend a whole lot more money on a 2cm capable GPS data logger like the Racelogic VBox 3i.

gplracerx wrote:EvolutionX,

It would be great if we could import the data into a program on the PC to see in big screen what's going on such as braking points, acceleration points and to be able to see our lines around the track.

You can. The export data function allows you to export lap or session data in a variety of formats. The two of most interest for your purpose would be .csv for importing into a spreadsheet and .vbo for importing into the free analysis program Circuit Tools. Importing non-VBOX video into Circuit Tools is non-trivial, but everything else works.

I'm not overly fond of Circuit Tools because it throws out the measured speed and acceleration data and recalculates it from GPS fixes. That's particularly bad for acceleration, even if you have a 20Hz GPS, as the double differentiation required for calculating acceleration from a position time series adds a lot of noise, which then requires a lot of filtering which, in turn, can result in significant distortion of the data. That's why I use a spreadsheet instead.

I don't think the ~2m minimum error on GPS data allows you to compare lines with sufficient precision to be of any value. For that, you would need to spend a whole lot more money on a 2cm capable GPS data logger like the Racelogic VBox 3i.

Any other analysis programs you would recommend?

Thanks

BACKGROUND VIDEO FOR ANDROID... Please, if possible?

I would like to be able to manually configure MIN and MAX THROTTLE values via an expert setting... the current method of deriving these values by observing the OBD values just isn't working. The Throttle PID replies with a range of 0-255, and varies greatly between vehicles.

In my case, with a PDK gearbox, when downshifting, there is an abnormally high value emitted for the throttle associated with a rev-match for the downshift.

LapTimer then uses that as the MAX, which you can never get with your right foot Then the rest of my overlays looks like I'm at 75% throttle, while my foot is actually down to the floor.

LapTimer isn't doing anything 'wrong'... but a workaround would allow users the manually enter values from 0-255 for MIN and MAX throttle. (expert setting).

One needs to do a OBD sensor trace to determine these values, which I have done previously.


Thanks for consideration