Harry's GPS Suite Forum

Harry wrote:You may recheck the basics: unpair the device, make sure no other device is accessing the Qstarz, remove the sensor entry in LapTimer, reboot the smartphone. Remove / kill any other app accessing It (helpers in particular).

Harry

Already did that multiple times. I have a vanilla install of a Samsung Galaxy Tab 4 7" tablet with only two applications added: SoloStorm and Harry's Lap Timer. If I have not installed a GPS helper, how would it get onto my system?

SoloStorm can access the QStarz without issue while Harry's cannot. SoloStorm does not show in the task list when closed or after a reboot. While Harry's can see the paired QStarz, it always shows "Not available" and defers to Samsung's internal GPS.

GPS Helper apps are typically provided by GPS manufacturers. Most apps do not have a direct GPS integration like LapTimer and cannot use the external GPS without such a helper app.

You may try uninstalling SS and check if it makes a difference.

Harry

I checked the SS's docs and they seem to install a background logger. Instead of uninstalling the complete app, you may switch it to internal GPS so it stops accessing the external GPS. To make sure it really doesn't, unpair the GPS afterwards and reboot the device to make sure the background service really doesn't access the BT device.

Harry

It has to be a conflict between the two softwares.

I have been able to get it work through this sequence of events:
Switch SS to Internal GPS and turn Logging on.
Launch HLT and go in Sensor List.
If "Not available", go back to SS, go back to HLT and check again. If still "Not available", go back to SS, close HLT, reopen, go to Sensor List and check again.
Repeat as necessary until "Connected @ 5 Hz".

If SS is switched to QStarz GPS, Logging is off, or SS is not running, HLT either cannot find the QStarz or cannot receive data from it.

Sounds too complicated, maybe SS needs to work a bit on resource allocation...

There is a notion of "good citizenship" in computer science. It describes principles like "free up any resource you do not use currently". As an example, LapTimer closes any sensor or other exclusive Android resource when it is sent to background. It (tries to) open it again once it is foregrounded. As a side effect, you can background and foreground LapTimer to reinitiate connection making. SS should immediately release the connection to the Qstarz in case the internal GPS is used or logging is turned off. From what you describe they do not currently.

As a last note: keep in mind the background logger uses lots of energy / battery when accessing the internal GPS. So in case you use LapTimer in foreground, I'd completely disable it to not run into overheating or excessive battery drain.

- Harry

SS has now been entirely removed from the system to aid troubleshooting.

For nearly 10 minutes, launching, closing, backgrounding and foregrounding, HLT was reading "Not available" on the QStarz. Randomly, I check and it is showing "Connected @ 5 Hz". Screen goes into power saving mode, I unlock the device, and now HLT cannot find it again...

In case the GPS lock is lost (which will frequently happen in closed rooms), LapTimer's update rate will go to 0 Hz. Same if you start up LapTimer inside, it may stay at 0 Hz (actually 0 Hz is not displayed, the rate is hidden for zero) too. 5 Hz means LT is getting 5 valid positions a second... To make sure the device is not going to power saving mode, switch to one of the timer views (Timer / Speedo) or real time analysis displays (GPS / Engine / Acceleration View).

- Harry

The persistent problem is it either shows "Not available" in the Sensor List or "Connected @ 5 Hz" but 0Hz in the GPS view when the screen is not locked. The issue is about the same whether SoloStorm is installed or not. Losing GPS after a screen lock is a problem, but if I can't connect to the sensor the first time I don't care about losing it if the screen locks.

I really work hard to find reasons for whatever configuration my valued customers run, but I start to run out of ideas. Maybe anyone else with a Galaxy Tab 4 can jump in. Sorry to repeat, but it is most probably some configuration / conflict or general BT stack issue for the Galaxy Tab 4. Please do not forget to check for any other BT device around probably disturbing operation.

- Harry

For me, i have only one bluetooth device paired ! My 818XT, so no conflict with other bluetooth device.

To use my external sensor with google map, i use bluetoothGPS app. It is working.
I was using this app before using HLT. But I never needed to use this application when i use HLT in July for exemple.
With this app, when the app is closed, there is no deamon in the background.

I tryed to :

* open HLT
* delete my external sensor link in HLT
* close HLT
* open Bluetooth GPS to link my external GPS data as internal
* open HLT
* go to HLT GPS view, and i am connected to 10Hz

So it is working but i think that is adding latency ? data error ? timming/precision error ?

If not, it can be a temporary solution for me to use HLT.


But i don't know why the app not working as befor without a "GPS HELPER".
i will continue to do different test but i don't know what doing