Searching \ for '[PIC]: 20Mhz oscillation' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: '20Mhz oscillation'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: 20Mhz oscillation'
2006\10\09@113534 by Ken Ouellette

picon face
HI,

I cannot get my 20Mhz oscillation to run.
I put my 4Mhz  crystal oscillator and it works. The
cystal is good, because i tested on the easyprog
board.
I added this line in my program :
DEFINE OSC 20 'Using 20MHz oscillator
but even then if I put my 4mhz it oscillates at 4Mhz
and never  witht the 20Mhz.
I supose there is a command to be put into the chip.
anybody knows ?

Thanks

ken



__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around
http://mail.yahoo.com

2006\10\09@115252 by Josh Koffman

face picon face
On 10/9/06, Ken Ouellette <spam_OUTlerameurTakeThisOuTspamyahoo.com> wrote:
> I cannot get my 20Mhz oscillation to run.
> I put my 4Mhz  crystal oscillator and it works. The
> cystal is good, because i tested on the easyprog
> board.
> I added this line in my program :
> DEFINE OSC 20 'Using 20MHz oscillator
> but even then if I put my 4mhz it oscillates at 4Mhz
> and never  witht the 20Mhz.
> I supose there is a command to be put into the chip.
> anybody knows ?

What PIC are you using? Are you setting it's CONFIG bits?

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
       -Douglas Adams

2006\10\09@115445 by Dave Wheeler

flavicon
face
Hi Ken,

Educated guess.....4Mhz will be happy with fuse set to XT where 20Mhz
will not and should be set to HS

Depending on whether you are using assembler, C or basic has an impact
on how the fuses are set.

Cheers,
Dave


Ken Ouellette wrote:
{Quote hidden}

2006\10\09@115945 by Wouter van Ooijen

face picon face
> I cannot get my 20Mhz oscillation to run.

=< 4 Mhz : config XT oscillator
>= 4 Mhz : config HS ocillator

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu


2006\10\09@121104 by John Chung

picon face
The crystal determine oscillation. To get a 20Mhz
oscillation you need a 20Mhz crystal.

John

--- Ken Ouellette <.....lerameurKILLspamspam@spam@yahoo.com> wrote:

{Quote hidden}

> --

2006\10\09@123128 by Ken Ouellette

picon face
Hello,

Ok got it now.
added this line

@ DEVICE HS_OSC

thanks
ken


--- Dave Wheeler <g0gmkspamKILLspambtinternet.com> wrote:

{Quote hidden}

> --

2006\10\09@145301 by Ken Ouellette

picon face
man , I am far from getting  a sin wave.
How can I get a sin wave out of this. I thought adding
a low pass filter will help me but no. Any ideas ?

thanks

ken


--- John Chung <.....kravnusKILLspamspam.....yahoo.com> wrote:

{Quote hidden}

2006\10\10@055528 by Dennis Crawley

picon face
Ken Ouellette <lerameurspamspam_OUTyahoo.com> wrote:
> man , I am far from getting  a sin wave.
> How can I get a sin wave out of this. I thought adding
> a low pass filter will help me but no. Any ideas ?
>
> thanks
>
> ken

Ken, you are trying to get 20Mhz sine wave? or
to get the "kit works" at 20Mhz?.

If the is the second, try to put a 18-22 pF capacitor to ground in each
crystal leg.

Regards,
Dennis.



2006\10\10@065325 by Ken Ouellette

picon face
well I have no kit. I got the microcontroller to work
but two problem. It is square wave , I will need an
integrator to make it sin wave. ( I will attempt to do
that unless you have a circuit for me)
And the program I use , the frequency is unstable, it
keep changing from 11khz to 31 khz even though I
configured it as follows.

loop:   FREQOUT PORTB.1,10000,20000              
Pause 100       ' Delay for .5 seconds

FREQOUT PORTB.1,10000,26000      
Pause 100       ' Delay for .5 seconds

FREQOUT PORTB.1,10000,21000            
Pause 100       ' Delay for .5 seconds

FREQOUT PORTB.1,10000,27000        
Pause 100       ' Delay for .5 seconds

Goto loop       ' Go back to loop



Alsoin the picbasic pro manual they say just to add a
low pass filter at the ouput to get a sin wave...

Ken


--- Dennis Crawley <@spam@dennis.crawleyKILLspamspamusa.net> wrote:

{Quote hidden}

> --

2006\10\10@080944 by Dennis Crawley

picon face
Ken Ouellette <RemoveMElerameurTakeThisOuTspamyahoo.com> wrote:
> Also in the picbasic pro manual they say just to add a
> low pass filter at the ouput to get a sin wave...
>
> Ken

Take a look to this thread at PICLIST
[EE] audio frequency sine oscillator help needed


More... (looser matching)
- Last day of these posts
- In 2006 , 2007 only
- Today
- New search...