I had left this on the backburner for a while, mainly because of the cost of the buttons would mean that creating a prototype would be a bit on the expensive side, and errors might end up bankrupting me.
Another conversation on a totally unrelated project reminded me of 'snap dome' buttons, which i had all but forgotten about. Much research later, and im ordering thousands of tiny metal domes for just a relatively small handful of cash. This means that the cost has dropped from $0.70 per button, to $0.03, making it much less of a problem if things dont go to plan.
After looking back to the pocket C.H.I.P that inspired the project to begin with, you can of course see that they have used snap dome switches for the keyboard!! not an intentional copy, but it does look like im heading the same way as they were. I am thinking that the domes will need a better covering though. Maybe having a layer of silicone cubes over the domes will make them easier to press, whilst also taking some of the sting out of them.
As an extra bonus, the 5mm domes i have chosen should allow some better placement, and routing, and maybe even a smaller (cheaper) PCB too!!
to be continued.....