Richard,
     I think BASIC is cool and I would use it instead of C or ASM if I=20
could find a good BASIC compiler that was free. I'm following you as you=20
do this. I'm using hardware to display my readings and I'm only using=20
the PIC to latch in the reading and then to clear the display in=20
preparation for the next reading.
Thanks,
rich!

On 7/19/2014 8:24 AM, Richard Pytelewski wrote:
> Dwayne:
>
> Just finishing project with similar reqt's.  Using the CCP in Capture mod=
e,
> and using TMR1, you can get excellent results.  FWIW:  use a good high fr=
eq
> crystal.... my measurements are in microseconds and anything but a crysta=
l
> will yield inconsistent results.
>
> I use ME Basic (OK, I know, BASIC is not cool) but here is my working cod=
e
> that may provide a start
>
> Detect:
>    T1CON   =3D   0x05                     ' TMR1 ON, 1:1 pre-scaler
>    CCP1CON =3D   0x05                     ' CCP Capture mode, every risin=
g edge
>    PIR1.5 =3D 0                           ' Clear bit 5
>    TMR1L    =3D 0                         ' Clear the TMR1L value
>    TMR1H    =3D 0                         ' Clear the TMR1H value
>    tim1 =3D 0                             ' Reset variable
>    while PIR1.5 =3D 0
>       nop
>    wend
>    if PIR1.5 =3D 1 then                   ' Capture occurred on rising ed=
ge
>      TMR1L    =3D 0                       ' Clear the TMR1L value
>      TMR1H    =3D 0                       ' Clear the TMR1H value
>      CCP1CON  =3D 0x04                    ' CCP Capture mode, every falli=
ng
> edge
>      PIR1.5 =3D 0                         ' Clear bit 5 (capture occurred=
 info)
>    end if
>    while PIR1.5 =3D 0
>        nop
>    wend
>      if PIR1.5 =3D 1 then                   ' Capture occurred on rising =
edge
>      tim1 =3D TMR1H<<8 + TMR1L            ' Retain TMR1 value =3D ON time
>      CCP1CON =3D 0x05                     ' CCP Capture mode, every risin=
g edge
>      PIR1.5 =3D 0                         ' Clear bit 2 (capture occurred=
 info)
>    end if
>    If tim1 <3700  then
>        TMR1L    =3D 0                     ' Clear the TMR1L value
>        TMR1H    =3D 0                     ' Clear the TMR1H value
>        tim1 =3D 0                         ' Reset variable
>        goto  Initialize_Detect
>    end if
>
> Rich
>
>

--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.