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Del Ogren
04-30-2006, 07:21 AM
Howdy, folks,

I'm a retired embeded systems programmer.· I bought a basic stamp development system
just to have something to fool around with when I get tired of working on other things.
Now I find that I have a job...

A friend of a friend is writing a PhD thesis on elephant communications and wants me
to make a low frequency audio tone generator.· No problem in Pbasic if I stick to square
waves, but I'd like to reduce the high frequency harmonics.· So I thought about driving
an R2R resistor network D/A converter.· But then, looking through the Pbasic manual,
I couldn't find any way to shove a nibble or a byte at the I/O pins in one statement.

Can this be done by writing into RAM?· Should I consider PWM?· Or should I just go
with square waves and a big cap to suck out the higher frequencies?

BTW..· I'd kinda like the frequency to be good to within 10 Hz or so..

Any guidance would be appreciated.

tnx,
--del

·

PJ Allen
04-30-2006, 08:34 AM
Del Ogden said...
·looking through the Pbasic manual,
I couldn't find any way to shove a nibble or a byte at the I/O pins in one statement.

BS2, et al. parallels out just fine.

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

DIRS = \$00ff ' P15-P08 = INs. P7-P0 = OUTs
OUTL = %00000000 ' all outputs to 0

parallel VAR byte

FOR parallel = 0 TO 255 ' this will rifle through \$00-FF
OUTL = parallel
next

parallel = %11110000 ' here's \$F0
OUTL = parallel

parallel = %00001111 ' here's \$0F
OUTL = parallel

END

Post Edited (PJ Allen) : 4/30/2006 1:37:55 AM GMT

Del Ogren
04-30-2006, 09:13 AM
Great! Thanks PJ,

Now I get the syntax...

You helped me RTFM..

--del

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Which end do end-users use?

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