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

[Albert ARIBAUD]

Bonjour,

Le Sun, 31 Jul 2016 20:51:51 +0100
Luke Kenneth Casson Leighton <lkcl at lkcl.net> a écrit:

> 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.

Hmm... Not getting what you're hinting at. Can you develop?

> > 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. :)  
> 
>  :)

I'll do that tomorrow evening, though. Real World is looming. :)

Amicalement,
-- 
Albert.