Monday, August 11, 2008

Re: [oopic] Reed switch help

On Aug 11, 2008, at 11:38 AM, ray xu wrote:

> The resistor acts as a pull-low resistor. A 10K-ohm or a 4.7K-Ohm
> is good

If all I am doing is counting pulses I try not to tie inputs to Vcc at
least not without a series resistor. Drive the input as an output and
you could smoke the pin. I would use the reed switch to ground and a
pull-up resistor to Vcc/Vdd. I agree with your value of 10K.

Vdd
|
10K
|
pin<-----+
|
reed switch
|
Vss (ground)


Brian Lloyd
Granite Bay Montessori School 9330 Sierra College Bl
brian AT gbmontessori DOT com Roseville, CA 95661
+1.916.367.2131 (voice) +1.791.912.8170 (fax)

PGP key ID: 12095C52A32A1B6C
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