Frequency Counter

[Will643]

Hi

I am trying to program a 16f88 PIC using Flowcode v4 to display a frequency to 4 decimal points. I am using an interrupt and tmr0 and can get a result displayed on an LCD as a whole number but not with decimal points as the counter result is an integer. Any help would be appreciated to get the result as a string or a float so i can display the result with a decimal point.

Thanks
Will

[JonnyW]

Hello. How are you storing the frequency - as an integer?

An integer is always a whole number - there is never any need to add a decimal point. If this is a particular requirement you can do:

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buffer = IntToString$(frequency)
buffer = buffer + "."

To add a '.' after the number.

If you are dividing by another number to get a fractional value, you can do this to a floating point result:

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freq = fdiv(int2float(multiplier), int2float(divisor))

Then you can use a float and use FloatToString$() in a string calculation box to display this. I would not do this in an interrupt though as floating point calculations and string conversions are slow.

Note in v5 this code can all be done in a single calculation box as:

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freq = int2float(multiplier) / divisor
buffer = FloatToString$(freq)

I hope this is what you are after or is something to go on.

Jonny

[jadiflow]

Johnny, if I may:

I have a problem with the FloatToString$ function.
It seems to work OK until the argument to FloatToString$ is larger than 32k.
Above a value of 32k, incorrect values are printed.
Is there a limit to the FloatToString$ function preventing it to convert values above 32k?

jan

[Benj]

Hi Jan,

Replied to you here.
http://www.matrixmultimedia.com/mmforum ... =7&t=10457

Please don't multi post if you can help it.