> -----Original Message-----
> From: Dwayne Reid [SMTP:dwayner@PLANET.EON.NET]
> Sent: Tuesday, March 11, 2003 5:40 PM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: [PIC]: Weak pull ups not so weak?
>
> At 10:35 AM 3/11/03 +0000, Michael Rigby-Jones wrote:
>
> >The resistors are not actually needed if the pins are never switched to
> >outputs.  If this is the case zero ohms would be fine.
>
> Series resistors are always a good idea when connecting to switches that
> might get zapped with an ESD hit.  One side of the switch should go
> directly to ground, the other side through a resistor to the PIC pin.
>
> The reason for using a series resistor is to limit the peak current and
> slow the rise time of the ESD spike that actually hits the PIC pin.
>
Agreed, although this is not overly relevant in this situation as the OP
circuit has the resistors between the switch and ground where it is unlikely
to protect the PIC in the event of an ESD hit.

Regards

Mike


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