After several reports by users running external GPS and OBD dongles, as well as information I received from my partner companies creating Mfi (Made for iPhones) devices, I need to inform you of the following issues with iOS7.1 and iOS7.1.1:
Data transfer is not possible for the Mfi device once it has been connected to an app (like Harry's LapTimer).
- A XGPS160, or a VBOX Sport, or a BT1A OBD is paired with an iPhone.
- LapTimer is started and makes a connection to the respective device (connection status is green in Sensor List).
- No data can be received, the update rate stays at 0 Hz.
- A XGPS160 is connected to an iPhone delivering 10 Hz to LapTimer.
- A BT1A is powered on and is connected to LapTimer.
- The XGPS160 stops delivering data.
- A XGPS160, or a VBOX Sport, or a BT1A OBD is connected to LapTimer and delivers data at a valid update rate.
- LapTimer is sent to background (disconnecting the accessory) and pulled to foreground after some time.
- The accessory is connected again but does not deliver data like before.
All accessories named above are samples. The problem seems to affect all Mfi devices. In general, the probability an accessory does not deliver data is the higher the more often it is disconnected and connected. As soon as more than one accessories are connected, the probability is very high one or all will not deliver data.
- Change to Sensor List and retry disconnecting (power cycling the accessory) and reconnecting.
- In case you see an accessory connected in Sensor List but not delivering data, send LapTimer to background and pull it forward again.
- In case you do not get data transfer working, send LapTimer to background and kill and restart it. This seems to clean up parts of the Bluetooth stack.
- In case you have not yet updated from iOS7 to iOS7.1, wait until you receive positive confirmation this problem has been fixed.
To not lose recordings completely, please check for a valid update rate each time you leave the pits. Once communication is working, it seems to be stable. But every interruption of the app and change to a different one, will probably stop data transfer. In case you use more than one accessory, please consider leaving all but one in the box currently.
This is a pretty cumbersome problem, especially as no ETA for a fix is available yet. Apple has confirmed this bug and is working on a bug fix. I'm told the fix will be part of iOS7.1.2 but this is not committed / confirmed. I will keep you posted.