Remap Left Spacebar key on MS Sculpt ergonomic keyboard

Question

I'm using the Microsoft Sculpt Keyboard with my Macbook Retina, on Yosemite. This ergonomic keyboard has a split Spacebar key, like so:

I want to remap the left Spacebar key to Backspace to simplify my typing. On Windows, a custom driver enables this remapping out of the box. However, this driver is not available on OS X.

I've already installed Karabiner and experimented with remapping keys. When I start up the EventViewer in Karabiner, both keys show up as KeyCode::SPACE. Is there a lower-level keycode I can access to differentiate between the left and right Spacebar keys?

Any alternate solutions are also welcome!

Answer 1

The best thing I've come up with so far is to use Right-Alt as backspace. Not quite as good, but it gets the job done.

Answer 2

You can not do this on Sculpt Ergonomic. Only on Sculpt Comfort https://support.microsoft.com/en-us/help/2757670/new-features-of-the-sculpt-comfort-keyboard

Answer 3

Found this answer:

By default, the functions of both the left spacebar and the right spacebar is to enter a space. If you want the customized function of the split space bar (where the left button acts as a backspace key and the right button acts as a space-bar key), to get activated, you need to press and hold left and right space bar at the same time for more than 3 seconds.

Seems like this is an keyboard function itself, not OS.