Measuring GPS update rates

[guitarZ]

Is there a way to measure the GPS update rates withing the TA application? Is it possible to add an indicator somewhere to the recording screen? The latter probably isn't a good idea, because you don't want a driver looking at the screen, but I wonder i f it's possible.

I had a quick look at the CSV file, and it looks like there is a time value with good enough precision so you could figure it out for yourself using a spreadsheet program, but I'm not sure how the time values are encoded (absolute, starting at time=0, I think.) There were 25 time values before it got to 1.0, so some help understanding the data file would be welcome.

I'm attaching a CSV file of about 50 rows or 2 seconds as an example.
Attachment 60816

[Weston@HPTuners]

The GPS icon in TrackAddict can help you with this... If you are on the Setup screen and tap on the GPS icon, it will display the current sampling rate. It wont do this on the Record screen because the design goal there is for the screen to be readable with a quick glance while people are driving, and wouldn't want to risk them inadvertently triggering popup dialogs during that time. On both screens, the GPS icon will also contain a small '+' when it's at 4Hz or more, to help you know that it's successfully connected to an enhanced GPS with a good signal (rather than the phone's internal 1 Hz GPS).

In the short CSV file that you attached, it would appear to be sampling at 1Hz. The times are in seconds, starting at zero. If you look at the GPS_Update column, you can tell that there are apparent GPS updates at 0.000, 0.031, 0.307, and 1.303... The first couple should usually be ignored as they were most likely queued up from before you started the recording. So, that leaves you with 0.307 and 1.303, which is 1 second apart, or 1 Hz. I would bet that the next one after that would be right around 2.303, within a few thousandths of a second.

[guitarZ]

OK, thanks, it makes sense. I didn't know you could tap the GPS icon!

the GPS status indicator:

GPS status.png

Apparently, my Dual XGPS 150 operates at 1 Hz, and I just updated the firmware to the latest version..

fwiw-
There is a thread on the Harry's Laptimer forum which says you can enable the 5Hz updates via some code.

[Weston@HPTuners]

That's correct... To get 5Hz on the XGPS150, you need their firmware update, and for an app to send some initialization data to set it to that mode.

If you have access to an iOS device, the iOS version of TrackAddict will do this automatically, and then it will work in 5Hz mode on Android as well (remember to change its mode switch between Apple and Android modes). Unfortunately, the data that is used to change this setting when its in Apple mode does not work when its in Android mode, so we're not able to automate this in the Android version of our app (there's apparently a different format we need to send, but haven't been told what it is).

[guitarZ]

Proprietary APIs are no fun. I'll say a prayer for you that Dual loosens up and lets programmers make use of the stuff. They may end up selling more GPS units!

Can you think of any reason for why Dual isn't cooperating?