Digital storage func. gen.

[Mark Steinberg]

I would like to build a "function generator" that will digitally store
a single cycle of 5-10 individual sinewaves, each with a frequency
between 5Hz-500Hz, and play any or all back continuously on demand.

It must be stand-alone and battery powered, ie. not PC or soundcard
based. However, a PC could be involved in generating the SW's to be
stored. But note the lower limit will not pass a soundcard.

I have no special requirements regarding resolution, voltage or
current output, other than the sinewaves look as much like a continous
sinewave on a CRO as is possible without going to extremes.

IOW I am open to suggestions regarding trade-offs between precision
and practicality.

What would be the most effective design path to follow for this,
stressing minimum complexity.

How would the sinewaves be loaded into the storage medium?

Thanks for any ideas.

Mark

 

[Frank Bemelman]

"Mark Steinberg" <mstein@locate102.com> schreef in bericht
news:2dbgu01ck49jf240h39ulkjatlprdq66c5@4ax.com...

I would like to build a "function generator" that will digitally store
a single cycle of 5-10 individual sinewaves, each with a frequency
between 5Hz-500Hz, and play any or all back continuously on demand.

It must be stand-alone and battery powered, ie. not PC or soundcard
based. However, a PC could be involved in generating the SW's to be
stored. But note the lower limit will not pass a soundcard.

I have no special requirements regarding resolution, voltage or
current output, other than the sinewaves look as much like a continous
sinewave on a CRO as is possible without going to extremes.

IOW I am open to suggestions regarding trade-offs between precision
and practicality.

What would be the most effective design path to follow for this,
stressing minimum complexity.

How would the sinewaves be loaded into the storage medium?

This is cheap:
http://www.myplace.nu/avr/minidds/

You could modify the software a bit, to get your 5-10 different
preset frequencies. No need to hook it up to a PC all the time.

--
Thanks, Frank.
(remove 'q' and 'invalid' when replying by email)

 

[Rene Tschaggelar]

Mark Steinberg wrote:

I would like to build a "function generator" that will digitally store
a single cycle of 5-10 individual sinewaves, each with a frequency
between 5Hz-500Hz, and play any or all back continuously on demand.

It must be stand-alone and battery powered, ie. not PC or soundcard
based. However, a PC could be involved in generating the SW's to be
stored. But note the lower limit will not pass a soundcard.

I have no special requirements regarding resolution, voltage or
current output, other than the sinewaves look as much like a continous
sinewave on a CRO as is possible without going to extremes.

IOW I am open to suggestions regarding trade-offs between precision
and practicality.

What would be the most effective design path to follow for this,
stressing minimum complexity.

If it is just for sinewaves, I suggest the use of a DDS.
Does sine nicely, from zero to several MHz, with uHz
resolution. Have a look at the AD9833
http://www.analog.com/en/prod/0,,770_843_AD9833%2C00.html

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
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