OK, fine.

We'll know better when we have more info about the
actual "ciruit". Right know the best guess is that
load capacitors for the crystal are missing.

If the caps are missing, just add them.

Jan-Erik.


jim wrote 2011-11-05 16:16:
> Disregarding your sarcasm, I was just stating why capacitors are used in =
a
> crystal circuit.
> Whether they are included in the circuit in question is as you say an
> unknown.  But for the
> point I was trying to make, it doesn't matter one way or the other.
>
> As far as it being a problem if they aren't included in this particular
> circuit?  Of course
> it could be.  No one said, at least certainly not me, that it wouldn't be=
 a
> problem.  As a
> matter of fact, my comment only supports the fact that it could be a
> problem, not dismisses it.
>
> And now regarding your sarcasm, I don't appreciate it at all.  I was just
> trying to make a
> circuit design point.  I was not trying to start an argument.
>
> Regards,
>
> Jim
>
>
>
> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf =
Of
> Jan-Erik Soderholm
> Sent: Saturday, November 05, 2011 8:38 AM
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC] IS this faulty?
>
> OK, whatever.
>
> We don't know for sure if there are any capacitors or not.
> And if not, isn't it a possible "problem" ?
> I think it is.
>
>
> jim wrote 2011-11-05 14:53:
>>
>> The main reason for the capacitors in a crystal circuit is to provide an
>> intentional imbalance between the input of the oscillator and output pin
> of
>> the oscillator so that when power is applied, the imbalance causess
> current
>> to flow, and thereby guarantees the oscillator will start oscillating.
>>
>> Jim
>>
>> -----Original Message-----
>> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
> Of
>> Isaac Marino Bavaresco
>> Sent: Saturday, November 05, 2011 7:45 AM
>> To: Microcontroller discussion list - Public.
>> Subject: Re: [PIC] IS this faulty?
>>
>> Em 5/11/2011 10:57, Jan-Erik Soderholm escreveu:
>>>>> I *think* that the header is useless without a target circuit.
>>>> But what is the smallest target circuit?I thought adding only crystal =
is
>>>> OK for starting debugging
>>> Right, but a crystal is useless without capacitors. And it is
>>> a bit unclear how the header is powered.
>>
>>
>> Not exactly. It may become unstable, or not to oscillate at all, but it
> may.
>>
>>
>>>> Sorry, I have just only  started with microchips  - so a lot  of new
>>>> knowledge for me to learn.
>>> It's not about learing PICs, it's about telling everything and
>>> not hiding details. :-)
>>
>>
>> By my experience with teaching newbies in electronics and
>> microcontrollers, it takes time to notice that there's missing
> information.
>> Because of this, I generally take it easy with them.
>>
>>
>> Isaac
>>
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.