Hey Lindy,
I'm curious, are you hooking this up to a piezo or some other speaker?


Lindy Mayfield wrote:

>>Texas Instruments used to make the SN76477 and the SN76496.
>>These are listed as "sound generators" and were meant to be
>>used in video games to produce a variety of sound effects. They
>>contained a noise source and various envelope generators.
>>The former chip (and maybe the latter) are no longer made, but
>>the
>>data sheets may be available somewhere. They showed how various
>>sounds were synthesized; this might give you some ideas.
>>
>>John Power
>
>
> This is an interesting subject.  I was looking at the embedinc website on their HAL project, and how they use PWM to make all sorts of sounds.  It went right over my head, but it gave me ideas to experiment with.
>
> Just the PWM output from this code produces a sound like a motor, sort of like the one from Pink Floyd's Welcome to the Machine:
>
> test
>         banksel T2CON
>         btfss           T2CON,TMR2IF
>         goto            $-1
>         banksel CCPR1L
>         decf            CCPR1L,f
>         banksel PR2
>         incf            PR2,f
>         goto            test
>
> So it got me to thinking that with the proper algorithms and maybe a little help from some simple wave shaping components, one could get an awful lot of good sounds from a PIC easily.
>
> Make the input voltage controlled and then it would be easy to build a sonar or IR controlled Theremin, or as another PIC project create a midi to control voltage converter.
>
> It also got me to thinking about the difference between using tables to produce a wave as opposed to using an algorithm.
>
>
>
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