PutDAC command output appears at Stereo Jack?

Started by ludovico90275 August 27, 2003
Hello,

I am planning to purchase the BasicX-35 Development System. I will
be creating an audio application that dynamically creates waveform
tables in the RAM sandwich area at runtime (not into EEPROM at debug
time). Therefore, the PlaySound command will not be used. I would
not want to change the sample rate everytime I need to change the
frequency (pitch) anyway.

My question concerns the PutDac command. Is this how I can send
audio waveform samples to the DAC directly and have them appear at
the Stereo Jack output on the development board?

Please send any specs on the DAC (is it 8 bit?) and the PutDAC
command that you may have.

Thanks




> ... the PutDac command. Is this how I can send audio waveform samples to
the DAC directly and have them appear at the Stereo Jack output on the
development board?

If you are planning on generating audio with a BX-24 (and I assume the
BX-35) you will encounter speed issues.

The tightest loop that the BX-24 can run that generates output (a squarewave
out on any digital pin) will spin at about 8KHz. That would limit you to a
4KHz upper cutoff according to Nyquist - but if you need an accurate
multipoint waveform at that frequency or higher even that won't do - and
that is with no other code running, and it is not stereo.

Assuming you're going to read input from somewhere and do some processing
before outputing an analog sample point, the highest frequency you will be
able to produce, I suspect, is probably more like 1KHz.

Good luck. Tom Becker
--... ...--
www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700