AVR-Chat

On Mon, 25 Sep 2006 07:56:11 -0500 (CDT) you wrote:

>On Mon, 25 Sep 2006, Ralph Hilton wrote:
>
>> On Mon, 25 Sep 2006 10:08:28 -0000 you wrote:
>> 
>> >Hi guys,
>> >
>> >I hope every thing is going OK.
>> >I`ve question hoping somebody could provide me what I have to do.
>> >How can I generate one second accurately to be applied Digital 
>> >Clock ? by the way, I`ve tried by Timer/Counter0 , T/C Prescaler , 
>> >Timer0 ovf0 (Int. Calling) but I didn`t get a real second .
>> >
>> >
>> >
>> >Plz help as soon as possible .
>> 
>> If you are using a crystal then there should be no problem getting a second by
>> dividing down with a timer. If you are using the internal RC then you can't get an
>> accurate second due to its lack of stability.
>> --
>> Ralph Hilton
>
>You can also use an external crystal oscillator with a trimmer cap for 
>frequency adjustment.  I've used a 10 MHz oscillator which I zero-beat 
>with WWV here. If you have a known frequency standard like a rubidium 
>standard handy, you can hook a scope up to the two outputs and adjust by 
>Lissajous figures.
>
>You can find 10 MHz OCXO's on eBay for $20 to $80.  I don't know how 
>desperately you need the accuracy; that may be overkill.

For a cheap TCXO Maxim make an inexpensive DS32KHz. They sent me 2 free samples on
request.
--
Ralph Hilton
http://www.ralphhilton.org
C-Meter: http://www.cmeter.org
FZAOINT http://www.fzaoint.net