Force OS X to use Bluetooth dongle instead of built in controller

Question

I'm using a Magic Mouse with my MacBook Pro and Mountain Lion. The cursor sometimes start to lag. I figured, the reason for this could be the distance between my Mac and the mouse (about 1.5 meters / 5 foot).

I bought an external USB Bluetooth dongle I want to plug into my monitor on my desk, so the mouse is closer to the controller. However, I can't figure out how to make OS X use the external dongle instead of the built in controller.

When I go into System Prefs > Bluetooth and hold the Option key to display the reception, I see that it is the strongest when it's next to my Mac and not when it's next to the dongle. So what can I do to change that? Thanks!

Answer 1

To force the system to use USB Bluetooth dongle by default, run the following command:

sudo nvram bluetoothHostControllerSwitchBehavior=always

^{This will modify your boot kernel arguments.}

To do opposite, use never. The change would be applied after the reboot. To return to the default, run:

sudo nvram -d bluetoothHostControllerSwitchBehavior

Answer 2

I just went through this using this no-name adapter on OS X 10.10: http://www.amazon.ca/dp/B00E38N7QE/ref=pe_386430_30332290_TE_3p_dp_1

The easiest way to use the USB adapter is to reboot. If you hold down the Option key while clicking on the Bluetooth menu icon, the MAC address of the adapter should be different. You can also verify in System Profiler. You'll know it's working if any existing pairings break.

I've found that a BT 4.0 adapter is working better than the built-in adapter in my 2010-era Macbook Pro. Especially with a headset, there's much better sound quality.

The on / off button in System Preferences is a little buggy. Turning off the adapter works fine, but clicking "on" turned the internal adapter back on. I had to unplug the adapter, plug it back in, and then turn Bluetooth back on.

If you want to work around this without rebooting, you can use Bluetooth Explorer from the OS X developer tools. You'll need a (free) developer account. There's a ton of useful tools to debug interference, pairing issues, and so on.

This is now part of a package called "Hardware IO Tools for Xcode V x.x" and can be found at https://developer.apple.com/downloads/

Answer 3

I've often had the exact same problem! I've found that the following method works consistently to switch to the external adapter. Starting with the external bluetooth dongle unplugged:

1. Turn off Bluetooth
2. Wait about three seconds
3. Plug in dongle
4. Again, wait about three seconds
5. Turn on Bluetooth

This works every time for me. No reboots or additional software required!

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Additionally, there's a much quicker way to see which bluetooth adapter your mac is currently using. With your external Bluetooth adapter unplugged:

1. If there's no Bluetooth icon in your menu bar, go to system prefs -> Bluetooth and check "Show Bluetooth in menu bar"
2. With the external dongle unplugged, option+click on the Bluetooth icon in your menu bar
3. Note the sequence of letters and numbers after "Address:". This is the name of your computer's internal Bluetooth adapter. (I usually just pay attention to the last two characters)

Now, try to switch to your external adapter, and repeat the above steps. If the address changes, your computer is definitely using the external adapter.

Answer 4

Looked in here: /Library/Preferences/SystemConfiguration. There i found a bluetooth plist file. I trashed it, rebooted, and then my USB dongle was finally recognized. I did not need to reset any SMC, NVRAM.

Answer 5

You shouldn't have that much of a reception issue from 1.5 meters. Even with some interference between the mini and your mouse, BT should be fine so I might be suspect of something else causing the issue rather than the Mac Mini BT card. But yeah, go into System Preferences > Bluetooth and turn it off.