Recently I got tired of my USB mouse wasting one of the three USB ports on my ThinkPad X220. So I started looking for a Bluetooth mouse and I found out the beautiful Microsoft Designer mouse, which I instantly bought on Amazon for 21 euros (got to admit, Microsoft does great hardware).

This mouse though supports only Bluetooth 4.0 (Bluetooth Low Energy) adapters, which meant I had to look for an hardware upgrade on my X220 as well. Turns out that the X220 is perfectly able to handle BLE cards, so I’m happily writing this post with the Designer mouse paired with my X220!

The Hardware

It was not clear if the X220 would support BLE adapters, but on eBay I found many sellers that claimed to have 4.0 cards supporting the X220. So I bought a Broadcom BCM20702 daughter board (part number FRU 60Y3303). If anyone has write-access on ThinkWiki, please update this page and add a note that the BCM20702 works on the X220 :)

The Software

The drivers for this card are already installed by the Linux kernel and everything works out of the box. You just need to start the pairing process by holding the button on the bottom of the mouse for five seconds. Plasma 5 detects the mouse just fine.

Designer Mouse in Plasma

The only thing I’m missing is that upower (and thus Plasma) doesn’t report the battery level of the mouse. I filed a bugreport about this, let’s see what happens.

Note that you may have a missing firmware warning in the dmesg output:

[    5.008076] bluetooth hci0: Direct firmware load for brcm/BCM20702A1-0a5c-21e6.hcd failed with error -2
[    5.008078] Bluetooth: hci0: BCM: Patch brcm/BCM20702A1-0a5c-21e6.hcd not found

This firmware can be installed from the T430s drivers as described here. The firmware helps with disconnections which are unfortunately quite frequent (at least in my experience). Without this firmware you would have to turn off the Bluetooth whenever the mouse stops working and then turn it on again.