I am also afraid that 'turning BT off' is not possible. At least not in an acceptable manner.
Why would I want to do that?
Simple. I have an iMac to which a secondary (VGA) monitor is connected. Also I have bought a Mini. So I wanted a switchbox to control 2 systems on a single monitor/keyboard/mouse. With a wired keyboard/mouse: no problem since a standard problem with a standard solution.
However I have a wireless keyboard/mouse and I enjoy both very much since I hate wires. (stronger: I hate mouse and love trackball but use the MM since I love wireless more).
Now it is feasible to connect 1 keyboardmouse to 2 systems but (as you can imagine) this is asking for problems since there is always the chance of a desastrous mouseclick on the systems that is not on the active monitor.
So I hoped that it would be possible to deactivate the internal BT, then put a BT-stick into the KVM device (where otherwise the keyboard/mouse goes) and then only 1 system gets the wanted action.
This is a little bit elaborate but hope you will understand what I want and why I thought it wise not to put this all in the original post.
This is really simple. The moment you plug in your external Bluetooth adpater, the computer will not use the internal Bluetooth module and will switch to the external one. I know, because I use a D-Link DBT-120 external Bluetooth adapter with my MacBook Pro which also has Bluetooth built-in.
I don't know about using it with a KVM, but I can tell you this, once you plug the external dongle into the USB, the internal bluetooth turns off.
How do I know? Here's my experience:
1. My external monitor sits several feet away from my MacBook Pro. I use a bluetooth keyboard and bluetooth mouse. Because I'm a bit far away form the MBP, the bluetooth connection using the internal bluetooth is not very reliable and often the mouse tracks unreliably. I bought a DBT-120 external bluetooth dongle and using a USB extension cable routed the dongle closer to where I'm sitting. Now, there are no problems with tracking etc.
2. When my mouse and keyboard is paired with the internal bluetooth, their respective names are CGYH Mouse, CGYH keyboard. When it is paired with the external, the names are conalho's Mouse, conalho's keyboard. I can check right now and yes, it is being paired with the external and not the internal.
So, I conclude, plugging in the external bluetooth dongle de-activates the internal bluetooth unit.
Now, whether or not it works with the KVM I don't know.
It indeed works that way. I was not sure since both times the kb/mouse got the same names.
However there remains (in my case) a problem.
With a KVM the BT-stick is connected to either machine meaning ont of the systems will not have the stick connected. As far as I have been able to deduct now I will be forced to reconnect each time that I switch system.
In my simulated try I connected the BT-stick then pulled it out of the USB-port and then plugged it in again. Both kb/mouse were not automatically connected but I had to go to the "Configure BT" menu (since mouse did not work I had to plug in a wired mouse). So not very usable.
Could this (disconnect and no automatic reconnect) be caused by the particular BT-stick or is this common? The BT-stick I used is a no-brand stick.
Perhaps, but your cell phone isn't using a dongle for it's BT communication.
Dongles generally drop BT pairing because they have no "smarts". They just do whatever the computer tells them to do.
Once you disconnect and then reattach that particular dongle the system must start all over again especially considering that once the external is unplugged the internal will try and kick in.
You may need to research a different way of doing this.
