> > Preferably all 380, but in the program I cut it down to 20Hz  to 255Hz.
> with
> > one value for each frequency. This was so that all the registers were kept
> as
> > 8bit . Also about 5% accuracy is alright.....I worked out a table
> > for each of the values.....just implementing it into the program is a
> > problem.. :)  I hope that helps.
>
> Saying "all" 380 makes no sense here, since there are an infinite number of
> frequencies between 20Hz and 400Hz  I guess you mean all the frequencies
> that happen to come out to integer values when measured in Herz?  OK, but
> that contradicts your 5% accuracy requirement.  400Hz/20Hz is a frequency
> range of 20:1.  At 5% accuracy, this can therefore be covered by Log1.05(20)
> = 62 different frequencies.  You need to decide what your requirements
> really are.
>
> A simple way to produce different tones is using the PWM output as a square
> wave generator.  However, the lowest frequency generated that way is
> oscillator/16,384.  You could use either a slow clock if the PIC has little
> else to do, or an external divider after the PWM output.
>
> Another way is to use timer 1 with a CCP module in compare mode.  This gets
> you a 16 bit period register.
>
> Another way is to do it all in software.  This is feasible in your case
> because your frequencies are so low.  Even a 12C508A can do this, but I
> don't know what other features you need to decide which frequency to emit.
>

Thanx for the help, the timer1 & CCP module thing sounds like what I need.
16bits is what I need :) I would still need to use the lookup table, right?


About the PWM, we have a choice of going that way or using DDS(Direct Digital
Synthesis:  for DDS theory
--->http://www.geocities.com/CapeCanaveral/5611/dds.html)
Although I will need to port it to a 16C717 or flash version of it, I think PWM
is the way to go.

BTW: I didnt make myself clear about the accuracy, because it was a
thumbsuck...:) But it does actually have to be accurate. esp. the higher Hz.
And I need to have the Hz. in integers, ie. (1,2,3,4,5.....399,400) Sorry about
that...

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