prescaler for pc-based frequency counter

[CSB]

Hi,
I have a freeware pc-based frequency counter (by BIP electronics lab),
that inputs signals from the soundcard in the 1-44100 hz range. If I
wanted to measure much higher frequencies (perhaps up to 500MHz if
possible), would a divide-by-whatever prescaler work for this? Has anyone
seen schematics for this kind of project? I thought of building a
standalone frequency counter, but I think it would be too expensive and or
complex for me. Thanks for any help,
CSB

 

[mike]

Hi,
I have a freeware pc-based frequency counter (by BIP electronics lab),
that inputs signals from the soundcard in the 1-44100 hz range. If I
wanted to measure much higher frequencies (perhaps up to 500MHz if
possible), would a divide-by-whatever prescaler work for this? Has
anyone seen schematics for this kind of project? I thought of building a
standalone frequency counter, but I think it would be too expensive and
or complex for me. Thanks for any help,
CSB

Question 1: Why do you think you need a counter...what are you gonna
do with it when you get it?
Question 2: How did you arrive at 500MHz? What are you gonna measure
there? Sensitivity required?

What you ask for is trivial. What you probably need is damn hard.

You can stack frequency dividers together to get almost any input
frequency you want.
Problem is that when you stuff the output into the sound card, the
resultant resolution and accuracy will be useless for anything I can
think of at 500 MHz...or 1MHz for that matter.
Just getting the signal in, protecting the input, stopping the
oscillations at 500MHz. is the fun part.

If you just want to learn about prescalers, hang together a couple of
flip-flops and stop at 1MHz. Sound card is still a useless toy, but
you can learn a lot from the exercise.

If you really want to measure frequency, go to a hamfest and buy a counter
cheap. If you really want to do useful stuff at 500 MHz. it won't be
quite so cheap.
mike

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[Jan Panteltje]

Hi,
I have a freeware pc-based frequency counter (by BIP electronics lab),
that inputs signals from the soundcard in the 1-44100 hz range. If I
wanted to measure much higher frequencies (perhaps up to 500MHz if
possible), would a divide-by-whatever prescaler work for this? Has anyone
seen schematics for this kind of project? I thought of building a
standalone frequency counter, but I think it would be too expensive and or
complex for me. Thanks for any help,
CSB

There is a nice 'standalone' PIC frequency counter (50MHz) with .asm listing
on the net, look for fmeter.asm in google, that will both work with LCD
text display and LED 7 segment display.
As to the pre-scaler, any chip that will interface to the PIC level should
do.
If you want to log data maybe you could then connect to the PC via RS232,
standalone is so much to be preferred.

There are many such projects for PIC, google
pic frequency counter 2100 links...

Now google 'prescaler chip' and bingo: 13600 hits! here is one (/64):

http://www.bitscope.com/design/hardware/?p=5
Have fun
JP