Searching \ for 'PIC16C84 Remote Frequency Counter Application' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/time.htm?key=count
Search entire site for: 'PIC16C84 Remote Frequency Counter Application'.

Truncated match.
PICList Thread
'PIC16C84 Remote Frequency Counter Application'
1996\04\29@030254 by Peter Homann

picon face
Hi,

I've done quite a bit of work with the 6805 and 8051 micro
variants. I am now looking to use a PIC due to their supurb features
and low power consumption.

I am planning to construct a remote frequency counter (personal
project), for a frequency in the range of 0 to 250 cycles/munute
(Quite low). It needs to calculate the frequency and output it in
a serial format at 2400 Baud.

The frequency is to be output at a maximum of one every 5 seconds,
and may be as slow as once every 15 seconds.

As for power requirements, I need it to
       1       Use as little poweras possible
       2       Run off 3 -3.3 volts.
       3       Use as slow an oscillator as possible, yet still provide
               the necessary frequency calculation accuracy.
       4       Utilise the low power modes where possible.

From what I can work out the 16C84 may be a good choice due to its
ease of programming and small package size.

What I'm looking for is any pointers on how to accomplish this. Any
applicable application notes, or other documentation that may help.

Note that I don't have WWW access, only anonoymous FTP facilities.

Any help or comments will be appreciated.

Thanks,

Peter.
--
_______________________________________________________________________
Peter Homann   email: spam_OUTpeterhTakeThisOuTspamadacel.com.au       Work : +61 3 9596-2991
Adacel Pty Ltd                                   Fax  : +61 3 9596-2960
250 Bay St, Brighton 3186, VIC, AUSTRALIA      Mobile :     014 025-925

1996\04\29@095628 by Stuart Allman

flavicon
face
>I've done quite a bit of work with the 6805 and 8051 micro
>variants. I am now looking to use a PIC due to their supurb features
>and low power consumption.
>
>I am planning to construct a remote frequency counter (personal
>project), for a frequency in the range of 0 to 250 cycles/munute
>(Quite low). It needs to calculate the frequency and output it in
>a serial format at 2400 Baud.
>
>The frequency is to be output at a maximum of one every 5 seconds,
>and may be as slow as once every 15 seconds.

At the University of Washington they are working on a fast pitch detection
algorithm.  I guess they looking at when the waveform repeats and how
closely it resembles the previous period.  So you could grab samples every
1/125 of a second and analyze the data in a similar manner.  You might want
to do this in MATLAB first, then port it.  Depending on the input, the other
way I can think of is to just count 0 crossings.

Stuart Allman
Studio Sound Design
.....studioKILLspamspam@spam@halcyon.com

1996\04\29@103547 by Chaipi Wijnbergen

flavicon
picon face
Hi Peter,

> I am planning to construct a remote frequency counter (personal
> project), for a frequency in the range of 0 to 250 cycles/munute
> (Quite low). It needs to calculate the frequency and output it in
> a serial format at 2400 Baud.
>
> The frequency is to be output at a maximum of one every 5 seconds,
> and may be as slow as once every 15 seconds.


I made something like it with the PIC16C74, it was designed to measure
frequencies up to about 50KHz.  it had one timer running in as a real
time clock in high frequncy (this was to allow for high resolution in the
frequncy measurment). then I opened the RB0 (external interrupt) mask for
some time and each time an interrupt arrived, I sampled the timer, then I
was able to say which time between pulses I have. there was alot more
averaging and noise cancelation in my algorith.

BUT, I think that for your application this is too complicated, what I
would do in your application is have one timer running in a frequency
that I would like to have a frequency resolution for and have another
timer count pulses in it's clock input. then precicly every 1 second I
will read the timer and see how many counts I had in the last second, so,
here you have the frequency.

Chaipi



                              \\\|///
                            \\  ~ ~  //
                             (  @ @  )
----------------------------oOOo-(_)-oOOo--------------------------------------
!                                                                             !
! Chaipi Wijnbergen                                                           !
! Electronics/Computer Eng. M.Sc.  Tel    : +972-8-9343079                    !
! Optical Imaging Laboratory       Fax    : +972-8-9344129                    !
! Brain Research Center            Email  : chaipispamKILLspamtohu0.weizmann.ac.il       !
! Weizmann Institute of Science    URL    : http://www.weizmann.ac.il/~chaipi !
! Rehovot 76100 ISRAEL             IPhone : chaipi                            !
!                                                                             !
------------------------------------Oooo.--------------------------------------
                         .oooO     (   )
                         (   )      ) /
                          \ (      (_/
                           \_)

1996\04\30@051105 by mike

flavicon
picon face
In message  <.....199604290625.AA29445KILLspamspam.....scratchy.adacel.com.au> EraseMEPICLISTspam_OUTspamTakeThisOuTMITVMA.MIT.EDU
writes:
> Hi,
>
> I am planning to construct a remote frequency counter (personal
> project), for a frequency in the range of 0 to 250 cycles/munute
> (Quite low). It needs to calculate the frequency and output it in
> a serial format at 2400 Baud.
>
> The frequency is to be output at a maximum of one every 5 seconds,
> and may be as slow as once every 15 seconds.
>
> As for power requirements, I need it to
>         1       Use as little poweras possible
>         2       Run off 3 -3.3 volts.


Peter,

You may already know this, but if not, Maxim do an RS232 converter chip
that runs from 3V to 5.5V and produces true RS232 levels.

It is the MAX 3232.

In fact I have run it on the bench with a C71 at less than 2V supply and
still they both worked!

Regards,

Mike Watson

--
Mayes(UK)

More... (looser matching)
- Last day of these posts
- In 1996 , 1997 only
- Today
- New search...