If it helps, sometime ago there was module code by Phil McCarley that used
a timer interrupt to do max197 readings at rates upto aprox 8KHz.
That would provide a starting point for the timer stuff. It used to be in
the files section of the yahoo group. If not get back to me by email.
On Fri, 9 Dec 2011, sunnyliu2005 wrote:
> Hi Kevin,
>
> Could you answer some question about your great gpio function here?
> What is the Linux Kernel version? Is it ts11 or 2.6.? ?
> Which one of the timer do you implement to work with gpio?
>
> --- In Kevin Cozens <> wrote:
> >
> > On 11-12-03 06:38 AM, Jim Jackson wrote:
> > > 50us is pretty small. Did you do any measurements to measure the jitter on
> > > the phase shift? Just interested in the sort of accuracy you could get.
> >
> > First, a correction. The phase shift wasn't 50uS, it was 25uS. I just
> > checked the project documentation and images captured from the scope.
> > At the start of the project I thought I wouldn't be able to get such a
> > small
> > phase delay but later I gave it a shot and was pleasantly surprised to find
> > it worked.
> >
> > With the main application running in a mostly idle state I noticed no
> > jitter. The most likely time for any jitter would be when the board is
> > counting pulses from a flow meter (using interrupts). I would expect some
> > jitter while dealing with up to a couple thousand interrupts per second but
> > I never had the scope hooked up while running those tests.
> >
>
>
>
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/ts-7000/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|