Raspberry Pi 

How to use GPIO pins with external module AND internal bluetooth interface (tested with Raspberry Pi Zero W)



Run raspi-config and enable the hardware serial. In the current version as of May 2020 you will find this setting under:

5 - Interface options
P6 - Serial

Answer the questions as:
- Would you like a login shell to be accessible over serial: NO
- Would you like the serial port hardware to be enabled: YES



remove console=serial0,115200

Example result:

console=tty1 root=PARTUUID=738a4d67-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait



# requires a static CPU frequency
# use force_turbo=1 for 400Mhz or core_freq=250 for 250Mhz



If bluetooth isn't installed yet, run:

sudo apt-get install pi-bluetooth