White noise using a BS2

Andy Fox

Does anyone have a schematic/circuit/hunk of code or know of a good sound generator IC that I could use with a BS2 to generate white noise of variable pitch/frequency?

It greatly confuses me that the BS1 has this ability via the SOUND command and that Parallex decided to drop that command in PBASIC 2.0 and 2.5.

Thanks.

Bruce Bates

Andy -

Perhaps you are looking for the FREQOUT command for the BS-2 Stamps?

Regards,

Bruce Bates

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TechnoRobbo

try:

x var word
do

pulsout 0,x & $3ff

low 0 'adding and subtracting low commands will change the pitch
low 0
low 0

loop

use a .o1microfarad cap to ground on pin

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Have Fun


TR

Andy Fox

TechnoRobbo said...
try:

x var word
do

pulsout 0,x & $3ff

low 0 'adding and subtracting low commands will change the pitch
low 0
low 0

loop

use a .o1microfarad cap to ground on pin

Hmmm. Crude but interesting! I think you forgot the "RANDOM x" line in the do-loop? Otherwise it just produces nothing or a steady tone.

This works, but only gets me into the mid-range frequency noise. I'd like to produce noise from a low rumble to a hiss using a BS2.

TechnoRobbo

yes I for got the random x.

Program actually looks like this

' {$STAMP BS2}
' {$PBASIC 2.5}

x VAR Word
OUTPUT 0

DO
RANDOM· x
PULSOUT 0,x & $3ff
LOW 0:LOW 0:LOW 0:LOW 0
LOOP

and it's a .1 not .01 uf cap, sorry.




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Have Fun


TR

Post Edited (TechnoRobbo) : 10/9/2007 11:11:42 PM GMT