Bluetooth
Note: Intel Wi-Fi users: If your Wi-Fi card supports Bluetooth, then the BT interface should be available out-of-the-box, as the required firmware is included in linux-firmware.
The Broadcom Bluetooth firmware is not available in the kernel (source), so you need to install bcm20702a1-firmwareAUR and reboot if you want to use Bluetooth.
Alternatively, you can retrieve the firmware directly from the Windows driver by yourself. You need to extract the .cab file with cabextract and then convert it to a .hcd file with hex2hcd from bluez-utils:
$ cabextract 20662520_6c535fbfa9dca0d07ab069e8918896086e2af0a7.cab
$ hex2hcd BCM20702A1_001.002.014.1443.1572.hex
# mv BCM20702A1_001.002.014.1443.1572.hcd /lib/firmware/brcm/BCM20702A1-0a5c-216f.hcd
# ln -rs /lib/firmware/brcm/BCM20702A1-0a5c-216f.hcd /lib/firmware/brcm/BCM20702A0-0a5c-216f.hcd
After reboot, the firmware is available for your Bluetooth interface.