If the PIC is set for RC mode, will there be a + voltage on one OSC pin and
a 0V on the other pin?  I am starting to wonder if something is wrong with
my programmer, and it's not setting the config. bits correctly.  From what
i've read, using XT or HS mode should produce a sine wave on one of the
pins, and even though I have it set for XT, I am getting the + and 0
volts...




-----Original Message-----
From: Olin Lathrop [mailto:olin_piclist@EMBEDINC.COM]
Sent: Monday, August 05, 2002 11:15 AM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [PIC]: AT-cut crystal


> I am trying to run a PIC18C452 from an ECS HC-49US crystal
> (http://www.ecsxtal.com/pdf2/hc-49us.pdf) It is a 4.000 MHz crystal and
the
> package says 20pF on the outside.  According to the datasheet for the PIC,
> it says that a series resistor may be needed for the crystal to function
> properly.  I have tried a 50K pot to vary this resistance,

That sounds way to high.  Start with 0 ohms and 22pF caps to ground at
either side of the crystal.  Keep the crystal close to the PIC, the leads
short, and observe good grounding techniques.  Then use the right oscillator
mode for that speed crystal.


**********************************************************************
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error please notify
the sender immediately.

This footnote also confirms that this email message has been swept by
MIMEsweeper and Symantec Norton AntiVirus for the presence
of computer viruses.
**********************************************************************

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads