All of this sound interesting but definitely ultra-technique and I'm kind of lost among all the informations found on this thread.
Then I will ask for help with my setup:
I have a RaspberryPi 3 with a fresh raspbian 2016-03-18 Jessie + Adafruit GPS ultimate hat + Adafruit 10-DOF IMU.
If I understand correctly, the new Bluetooth device on the RPi3 is "mapped" to GPIO 14&15 i.e TXD&RXD for UART bus.
The problem here is that Adafruit GPS ultimate hat also use GPIO 14&15 for data.
Conclusion: we have a conflict because only 1 device can use TXD&RXD.
Am I understanding the problem correctly ?
Obviously my goal is to get the Adafruit GPS ultimate hat working. Ideally I would get bluetooth working too but my project does not require bluetooth so it's not an important feature for me. (But who know... maybe I can require it later, so keep it working)
Again, if I understand well the RPi3 has 2 UART bus, one is powerful, the other one is less powerful and of course the Bluetooth device is "mapped" to the powerful UART bus, right ?
So because bluetooth is less important for my project I would ideally map the bluetooth device to the less powerful UART bus, then map the powerful UART bus to GPIO14&15 that way my Adafruit GPS ultimate hat can be used normally with gpsd (at least that's the plan !)
The question are: how to achieve this plan ? Once GPIO14&15 are mapped to my Adafruit GPS ultimate hat, where are received data: /dev/ttyS0 ? /dev/ttyAMA0 ?
I'm asking because I'm lost, I don't know if I need "dtoverlay=pi3-miniuart-bt" or/and "core_freq=250". Should I edit hciuart.service ? or should I simply follow the tutorial available at https://www.abelectronics.co.uk/kb/arti ... port-usage
Thanks in advance for those who will take the time to explain and answer with understandable wording for a non-expert like me