On Sun, Jul 31, 2016 at 8:34 PM, Albert ARIBAUD <[email protected]> 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. :) :) _______________________________________________ arm-netbook mailing list [email protected] http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to [email protected]
