A CCP module is restricted to multiples of the instruction rate. This will
not let the user to get exactly 440Hz.

I would recommend a DDS solution. This could have as little as one bit of
output, or it could use a lookup table and the PWM device to generate a nice
pretty sine wave.

Bob Ammerman
RAm Systems

----- Original Message -----
From: "Spehro Pefhany" <speff@INTERLOG.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Wednesday, January 07, 2004 9:31 AM
Subject: Re: [PIC:] Frequency dividing to 440 Hz


> At 03:09 PM 1/7/2004 +0100, you wrote:
> >Hi all,
> >
> >I am now designing a electronic metronome for myself, PIC-based of
course.
> >As an extra, since I'm using crystal precision anyway, I thought of
> >including a 440 Hz (an A note) reference tone to tune flutes etc.
> >But I can't find any standard (cheap) crystal that divides nicely in 440
Hz.
> >Do you know a simple solution, that does not introduce audible jitter
> >(that would effectively ruin the use as a tuner)?
> >Are self-adjusting timer loops good enough?
> >
> >Well, thanks in advance again,
>
> How about just using a capture-compare module and whatever crystal you
like?
>
> Best regards,
>
> Spehro Pefhany --"it's the network..."            "The Journey is the
reward"
> speff@interlog.com             Info for manufacturers:
http://www.trexon.com
> Embedded software/hardware/analog  Info for designers:
http://www.speff.com
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

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