[Arm-netbook] EOMA-68 laptop Keyboard support improvement pushed

[Luke Kenneth Casson Leighton]

On Sun, Jul 31, 2016 at 8:34 PM, Albert ARIBAUD <albert.aribaud at free.fr> wrote:

> Thinking more about it, maybe you were thinking about up to 16 keys
> being depressed rather than 8, and the inputs' fan-ins adding up to
> twice more and the output's fan-out not being able to cope, leading to
> the input voltage not falling low enough for the keys to be detected
> as down.

 not quite... maybe i was but hadn't quite got it through from
subconscious into words.. but that's a good point - i was thinking if
you used 8 fan-in and press 9 keys... if you have 16 fan-in and press
9 keys...

 basically the 16 fan-in it "activates" 50% less of the matrix.

> Technically, I should have taken the switches' impedance (about 200
> Ohm) into account in case it worsens things; but those 200 Ohms
> would increase the pull-up impedance and reduce the current, so
> actually a 0 Ohm switch impedance is the worst case already.
>
> So I think that's OK, but you know what? Let me try it. :)

 :)