Richard P. will bounce you for putting this forward like I said this on the 16th may. We used to do this on alarm contacts so that there was a delay before alarm threshold was reached. also it cut down false alarms. Art. ----- Original Message ----- From: "Peter L. Peres" To: Sent: Tuesday, May 21, 2002 7:35 PM Subject: Re: [PIC]: There are more things in heaven and earth, Horatio, > On Tue, 21 May 2002, Jinx wrote: > > >> Bouncing at bottom contact will produce 0 - 0.5 Vdd noise. > >> Bouncing at top contact will produce 0.5 - 1 Vdd noise. > > > >Exsqueeze me ? > > > >Noise coming from the switch will be 0-5V regardless. It > >must be as a consequence of the contacts touching or > >otherwise the switch wouldn't be a switch, unless it came > >from the Pisspoor Switch Co catalogue > > The bounces are so fast that the line capacitance does not allow them to > raise/drop fully fefore the next one comes. This is how simple > capacitor-only debouncing works. There are several hardware debouncing > schemes that do not like this kind of noise, and fail. > > Peter > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu