Also check out the
Azeron, with some keys similar to how the Datahand does it. Check also
the makers' prototype-thread with more pictures of the mechanisms.
Quite a few home-made 3D-printed ergo keyboards have a thumb-cluster with the keys angled towards each other.
DMOTE is one, but a 4×4 cluster is more common. The
Atlas56 has a
hole for the thumb with keys up/down/left/right.
Heh, I almost posted a link to
your keyboard with 6-direction D-pad modifier keys, before I saw who asked.
The Microsoft Arc keyboard used a square D-pad instead of arrow keys: everyone hated it.
D-pads are usually done with a rubber dome switch in each direction and a fulcrum in the middle to prevent opposite directions from being activated at once. The downside of that design is that it is limited to four directions and diagonals, and that the diagonals have different engagement distance and required force.
The
NeoGeo CD's D-pad is different: more like a thumb-stick with an arcade joystick inside.
I would like to know a mechanism for a D-pad that is tactile like rubber dome D-pad but with with equal force and engagement/actuation distance in all directions, but I have not found it. Once a mechanism for tactile tilt exists then the sensing of direction some other way. I have a keyboard with an analogue joystick for mouse control and I think that one uses hall-effect sensors. (at least the four sensors are marked HED0..HED3 on the PCB)
Maybe "touch sensors" could be used also. "Touch sensor" is a misnomer though, as it is more like a sensor of a finger coming into a certain range, so they have to be tuned for the right distance between electric pad and touch-surface.
The
Steam Controller uses a dished capacitive touch-surface instead of D-pad.
Apple mice use a single "button" (actually, rocking the entire mouse forward) but distinguish left and right "clicks" using touch sensors on top of the mouse.
The failed
TextBlade Portable Keyboard used a single key per column, with touch sensors to figure out where on the key each press occurred. A key did not even contain a regular switch: just a spring and scissor mechanism. The touch sensors were stationary below the key and a press was sensed by the finger-tip being at the bottom of the press and thus close to the sensor.
There are also a few home-made few ergo keyboards that have used a sliding 5-way digital mini-joystick:
"Nav Switch".
