Harry's GPS Suite Forum

I strongly recommend turning off Location Services in the Privacy screen when using an HLT compatible external GPS like the Emprum Ultimate or the VBOX Sport. You don't need it in HLT. In fact, it can cause problems with accurately setting POI's. Location Services has some sort of time filter so it isn't always exactly where your GPS says you are. Turning it off solves that problem.

I am using a Dual Universal GPS Receiver with my iPhone5. When I turned Location Services off, HLT no longer had access to the GPS information from the external GPS receiver. Per Harry, "LapTimer will turn off the internal GPS once it connects to an external GPS."

Turning off location services is not only a physical switch for the internal GPS sensor, but changes several security settings (including access to the Photo library). This is the reason I recommend to enable Location Services when using LapTimer. The internal chip is not used by LapTimer when an external GPS is connected - as documented. So there is no disadvantage having it turned on (except a very special case when using the Map View with an iPod touch gplracerx ran into). You can see access to the internal GPS by watching the small arrow in your iPhone's status bar. One addition: there are several apps available gathering positions in background (using location services). In case you do not want to have LS run in background, don't use these apps.

- Harry

I ran an autocross this weekend with Location Services off and a Dual XGPS160 with no problem, but I wasn't using video. The HLT times were nearly identical to the official times. I had to reboot several times on Saturday, but not on Sunday. I think it helps to forget all the Bluetooth devices, not just the GPS, and kill all running apps before rebooting.

I'm not sure why I had trouble the first time, but I likewise was able to run LapTimer succesfully with Location Services turned off. In fact I had to turn it off in order to get the Dual XGPS150 to communicate successfully with LapTimer. This has happened intermittently when I have altered settings. When the Dual XGPS150 connects but does not show an update frequency, there is no data coming across. The fix is to either reboot the phone or to turn off Location Services.

I tried Airplane Mode with LS off and BT enabled, and successfully recorded iPhone video and got GPS and OBD data from Dual XGPS150 and GoPoint BT1. After rebooting, I tried Airplane mode with LS on and BT enabled, which also worked fine. Note that Harry has advised against using Airplane mode since he has not done extensive testing, but it worked fine with my configuration, which includes an external GPS unit. If you decide to try this, be sure to re-enable bluetooth and/or wifi as needed since these will be automatically disabled when Airplane mode is turned on but can then be overriden. I don't know what if any impact this would have on multicam functionality.