gnupic: pulse counting using timer1
Subject:
Re: pulse counting using timer1
From:
Laurence Withers ####@####.####
Date:
5 Apr 2004 00:59:23 +0100
Message-Id: <200404050058.50054.lwithers@users.sf.net>
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On Monday 05 April 2004 00:42, Phil wrote:
> Now that the counter works I've found that the circuit is very
> sensitive to electrical noise. Turning on or off nearby appliances
> causes the count to advance, sometimes by hundreds and this is with
> the PIC circuit being battery powered and port C0 grounded.
Have you decoupled the PIC? (A 0.1uF capacitor across the supply pins,
located physically close to the chip, should do the job). Also, you
could experiment with decoupling RC0 as well -- just run a capacitor
from the pin to ground. Finally, try to use the same technique to
dampen noise at whatever source your pulses are coming from.
The idea is that at higher frequencies (i.e. the noise you want to
avoid), the capacitor's impedance falls and so it drains away some of
the noisy signal.
Bye for now,
- --
Laurence Withers, ####@####.#### ####@####.####
http://xmlpcbrender.sf.net/ http://lw-gui.sf.net/
http://pgp.dtype.org:11371/pks/lookup?op=get&search=0x04A646EA
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