Instead it can use whatever is connected to it.
For example someone attached a vibrating belt that always vibrated on the north side of his body. After a while the person wearing it does not consciously notice it vibrating, instead they basically have a new sense - they just always "know" where north is.
Output works the same way - after playing a game for a while you don't need to think: press this finger or that one - you just want the character to do move, and your fingers do it automatically.
If you use a tool for a long time, it essentially becomes (to the brain) an extension of your body.
So same with this device - it doesn't have to be intuitive - after a while it simply becomes a part of his body. The brain does not see it as "else" it's simply another limb.