edge detection

Archiver

I need to monitor an input and detect a rising or falling edge. Upon
detection run a serial input routine. The pulse is one input and the
serial stream is another.

Archiver

Then this is very simple:
loop:
if INx = 1 then goto yourroutine (use = 0 if want to detect falling
edge) (x is your pin number)
goto loop

ACJacques

djarmis@p... wrote:
>
> While it's looking for the edge it won't be doing anything else. The
> program will just wait for the edge to occur. When it detects it I
> will need to go to a routine that will read some serial bytes in. I
> looked at the button command but not sure what it does. Thanks,
>
> --- In basicstamps@egroups.com, LarryGaminde <lgaminde@t...> wrote:
> > Is this all the chip needs to do, or will it be reading or doing
> other
> > things while looking for a rising or falling edge.
> >
> > djarmis@p... wrote:
> > >
> > > I need to monitor an input and detect a rising or falling edge.
> Upon
> > > detection run a serial input routine. The pulse is one input and
> the
> > > serial stream is another.

Archiver

Is this all the chip needs to do, or will it be reading or doing other
things while looking for a rising or falling edge.

djarmis@p... wrote:
>
> I need to monitor an input and detect a rising or falling edge. Upon
> detection run a serial input routine. The pulse is one input and the
> serial stream is another.

Archiver

While it's looking for the edge it won't be doing anything else. The
program will just wait for the edge to occur. When it detects it I
will need to go to a routine that will read some serial bytes in. I
looked at the button command but not sure what it does. Thanks,

--- In basicstamps@egroups.com, LarryGaminde <lgaminde@t...> wrote:
> Is this all the chip needs to do, or will it be reading or doing
other
> things while looking for a rising or falling edge.
>
> djarmis@p... wrote:
> >
> > I need to monitor an input and detect a rising or falling edge.
Upon
> > detection run a serial input routine. The pulse is one input and
the
> > serial stream is another.

Archiver

The signal I'm detecting the edge on is a repetitive square wave. It's
possible that at the time the if INx=1 statement occurs the level
could be high. Would this satisfy the if statement or does INx only
look for a transition from a 0 to a 1? I'm new to Stamps and no little
about the language so I may be asking a dump question. Thanks,



--- In basicstamps@egroups.com, "A.C.Jacques" <acjacques@i...> wrote:
> Then this is very simple:
> loop:
> if INx = 1 then goto yourroutine (use = 0 if want to detect falling
> edge) (x is your pin number)
> goto loop
>
> ACJacques
>
> djarmis@p... wrote:
> >
> > While it's looking for the edge it won't be doing anything else.
The
> > program will just wait for the edge to occur. When it detects it I
> > will need to go to a routine that will read some serial bytes in.
I
> > looked at the button command but not sure what it does. Thanks,
> >
> > --- In basicstamps@egroups.com, LarryGaminde <lgaminde@t...>
wrote:
> > > Is this all the chip needs to do, or will it be reading or doing
> > other
> > > things while looking for a rising or falling edge.
> > >
> > > djarmis@p... wrote:
> > > >
> > > > I need to monitor an input and detect a rising or falling
edge.
> > Upon
> > > > detection run a serial input routine. The pulse is one input
and
> > the
> > > > serial stream is another.

Archiver

The statment if INx= 1 looks only for a high state no the transition
itself but if your square wave have a lower frequency than the loop then
it will go to routine very close with the rising edge. But there are no
garantee that the first entrance in the loop the statement will be close
to the edge. To do this you may look for two transitions:

loop:
if inx = 1 then loop: (only wiil goto next line if state is low)
if inx = 1 then your routine
goto loop:

ACJacques



djarmis@p... wrote:
>
> The signal I'm detecting the edge on is a repetitive square wave. It's
> possible that at the time the if INx=1 statement occurs the level
> could be high. Would this satisfy the if statement or does INx only
> look for a transition from a 0 to a 1? I'm new to Stamps and no little
> about the language so I may be asking a dump question. Thanks,
>
> --- In basicstamps@egroups.com, "A.C.Jacques" <acjacques@i...> wrote:
> > Then this is very simple:
> > loop:
> > if INx = 1 then goto yourroutine (use = 0 if want to detect falling
> > edge) (x is your pin number)
> > goto loop
> >
> > ACJacques
> >
> > djarmis@p... wrote:
> > >
> > > While it's looking for the edge it won't be doing anything else.
> The
> > > program will just wait for the edge to occur. When it detects it I
> > > will need to go to a routine that will read some serial bytes in.
> I
> > > looked at the button command but not sure what it does. Thanks,
> > >
> > > --- In basicstamps@egroups.com, LarryGaminde <lgaminde@t...>
> wrote:
> > > > Is this all the chip needs to do, or will it be reading or doing
> > > other
> > > > things while looking for a rising or falling edge.
> > > >
> > > > djarmis@p... wrote:
> > > > >
> > > > > I need to monitor an input and detect a rising or falling
> edge.
> > > Upon
> > > > > detection run a serial input routine. The pulse is one input
> and
> > > the
> > > > > serial stream is another.