Thanks.

I was looking more for simulated sounds, and examples of how to generate
white noise, pink noise, buzzing, chirping, sirens, etc with a small
cheapo pic.  Precision isn't necessary, and direct drive with a square
wave is fine.

I am looking for noises that are annoying to animals, but are audible
and tolerable to humans... perhaps a difficult task.

Craig


> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Philippe
> Sent: May 28, 1999 10:13 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: White noise generator
>
>
> At 09:43 28/05/99 -0600, you wrote:
> >Speaking of pic sound code, does anyone have code/circuitry examples
> >for generating white noise, etc.
> >
> >I was thinking of using a 12C509 and direct driving an element from
> >an I/O pin with PWM.  Then varying the duty cycle register with a
> >random number generator.  Do I have to vary the frequency too?
>
> You will find a PWM Sound generato example with UMPS, a project
> file called 84SNDPWM.PRJ show how it is possible to generate PWM
> sound. This can also be used to translate a recorded table directly
> as PWM output. UMPS will simulate that, record the waveform, resample
> it at 22KHz and resend it to your sound card if you have one. It
> will also create .WAV file that can be analysed after if necessary using
> a WAV viewer or other WAV tools.
>
> Give it a try:   www.vmdesign.com
>
> Regards,
>         Philippe.
>