When I try to configure the SIRF of the Jentro BT-GPS-8U, I run into the following issue:
Bluegps4Android tries to switch to Sirf binary mode and back to nmea. Somewhere in that process, it apparently configures the 34800 baud rate (guessing from the string name "sirf_bin_to_nmea_38400_alt"). The Jentro device however uses an internal baud rate of 57600 between its bluetooth module and the sirf module. If the sirf module is configured to a different baud rate, it becomes inacessible to the bluetooth module, thus the baud rate cannot be reset. The device is bricked.
This state usually lasts until the internal battery of the device is fully exhausted (hours, and not very healthy for the battery). The only way to reset it before this is to open the device and short or physically disconnect the battery for some seconds.
I have soldered a switch to the battery and can now test this reliably.
Introduce more configuration options, different possibilities:
1. Include different baud rates into binary sirf options. (This is preferable, because it retains full functionality)
2. Include option to not change static navigation and Waas/Egnos. The remaining options (message rates) can be configured using pure NMEA. (This may be easier, because an option to disable binary sirf communction while retaining message rate configuration should be sufficient)