On Mon, 2 Jan 2006, Howard Winter wrote:

> Peter,
>
> On Sun, 1 Jan 2006 20:20:58 +0200 (IST), Peter wrote:
>
>> On Sat, 31 Dec 2005, Wouter van Ooijen wrote:
>>
>>> The ganssle document is nice, but it does not mention down-state
>>> bouncing.
>>
>> Down state bouncing seldomly occurs with new keys. It happens with
>> 'rubber' keys and oxydized contacts or weak springs.
>
> Right, but if you rely on that you are building obsolescence into your 
> software, since mechanical switches do change as they age, but are 
> still usable even with a noisy signal if you debounce properly.

I do not follow you here. Rely on what ? Some new rubber keys cannot 
make their mind up whether they are up or down after 10 pushes. 
Metal/metal pushbuttons can start to show signs of old age after six 
months. I was advocating debouncing for both up and down, in software. 
Maybe I made myself misundestood ;-)

Peter
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