RPi4B files for bluetooth headsets on Arch Linux ARM 4.19

btuart

#!/bin/sh

HCIATTACH=/usr/bin/hciattach
if grep -q "Pi 4" /proc/device-tree/model; then
  BDADDR=
else
  SERIAL=`cat /proc/device-tree/serial-number | cut -c9-`
  B1=`echo $SERIAL | cut -c3-4`
  B2=`echo $SERIAL | cut -c5-6`
  B3=`echo $SERIAL | cut -c7-8`
  BDADDR=`printf b8:27:eb:%02x:%02x:%02x $((0x$B1 ^ 0xaa)) $((0x$B2 ^ 0xaa)) $((0x$B3 ^ 0xaa))`
fi

uart0="`cat /proc/device-tree/aliases/uart0`"
serial1="`cat /proc/device-tree/aliases/serial1`"

if [ "$uart0" = "$serial1" ] ; then
	uart0_pins="`wc -c /proc/device-tree/soc/gpio@7e200000/uart0_pins/brcm\,pins | cut -f 1 -d ' '`"
	if [ "$uart0_pins" = "16" ] ; then
		$HCIATTACH /dev/serial1 bcm43xx 3000000 flow - $BDADDR
	else
		$HCIATTACH /dev/serial1 bcm43xx 921600 noflow - $BDADDR
	fi
else
	$HCIATTACH /dev/serial1 bcm43xx 460800 noflow - $BDADDR
fi

hciuart.service

[Unit]
Description=Configure Bluetooth Modems connected by UART
#ConditionFileNotEmpty=/proc/device-tree/soc/gpio@7e200000/bt_pins/brcm,pins
Requires=dev-serial1.device
After=dev-serial1.device

[Service]
Type=forking
ExecStart=/usr/bin/btuart

[Install]
WantedBy=multi-user.target

raw script

sudo pacman -S pulseaudio-alsa pulseaudio-bluetooth bluez-utils libmm-glib modemmanager
sudo systemctl start ModemManager
sudo systemctl enable ModemManager
sudo systemctl start bluetooth
sudo systemctl enable bluetooth

## copy btuart to /usr/bin folder and chmod 777
sudo cp <your folder containing file>/btuart /usr/bin/.
sudo chmod 777 /usr/bin/btuart

## copy hciuart.service to /etc/systemd/system folder
sudo cp <your folder containing file>/hciuart.service /etc/systemd/system/.

# Add permanent link for serial1 as udev rule:
sudo nano /etc/udev/rules.d/99_ttyAMA0.rules 
KERNEL=="ttyAMA0", SYMLINK+="serial1"

reboot

cd /home/<your folder>
git clone https://aur.archlinux.org/hciattach-rpi3.git
cd hciattach-rpi3/
makepkg -Asri

sudo cp /usr/bin/hciattach-rpi3 /usr/bin/hciattach
sudo systemctl start bluetooth
sudo systemctl enable bluetooth
sudo systemctl start hciuart
sudo systemctl enable hciuart

bluetoothctl
#[bluetooth]power on
#[bluetooth]scan on
#(Multiple bluetooth devices in your area should appear per line with MAC addresses)
#[bluetooth]pair <yourheadset as: ##:##:##:##:##:##>
#[yourheadset brand]connect ##:##:##:##:##:##
#[yourheadset brand]trust ##:##:##:##:##:##

# ADD two lines below somewhere near the top of lists in this file: 
sudo nano /etc/pulse/default.pa

# Automatically switch to newly-connected devices
load-module module-switch-on-connect

# Uncomment and set `AutoEnable=true` in [Policy] section of the file:
sudo nano /etc/bluetooth/main.conf

reboot