With macOS Monterey, Apple has rewritten the bluetooth stack with 2 main changes:

• Move Bluetooth Stack from kernelspace to userspace
• Drop legacy support for BCM2046 Bluetooth Modules

Due to this, many legacy Macs have lost bluetooth support outright. Newer modules based off the BCM2070 chipset are not affected as they're designed to retain their firmware, and only BCM2046 need their firmware loaded on each boot.

Within macOS Monterey, Apple stores Bluetooth firmware under /usr/share/firmware/ and loads these firmwares with a new tool called BlueTool residing under /usr/sbin/. Device IDs are hard coded however could be patched to allow a wider array of devices.

Affected Devices

Currently the following BCM2046 Bluetooth chipsets have lost support:

• 05AC,820F
• 05AC,8210
• 05AC,8213
• 05AC,8215
• 05AC,8216

Additionally, the following models are affected:

• iMac12,x and older
• Macmini4,1 and older
• MacBook7,x and older
• MacBookAir4,1 and older
• MacBookPro8,x and older
• MacPro5,1 and older

Work Arounds

Currently we recommend users search for native Bluetooth chipsets as we're unsure when we may be able to implement a proper solution. Currently the following chipsets have native support within macOS:

• BCM2070 (Bluetooth 3.0)
• BCM20702 (Bluetooth 4.0)
• BCM20703 (Bluetooth 4.1/4.2)

Additionally the following Wireless Modules have natively supported Bluetooth chipsets bundled in:

• BCM943224
• BCM94331
• BCM94360
• BCM943602