PWM to Soundcard ?

[S.S.]

I need a Width-modulated Pulse Signal (square) at the Line-out Plug of my
Soundcard.
My Vis makes only crash-Sounds but no fine Signal.
I took a normal Function-Generator and put it to Sount-Write...but it does
not work.

Has somebody an Idea or a ready made VI for this Problem ?

Best regards

Message Edited by Support on 09-24-2008 03:55 PM

[Labviewguru]

I did this exact thing with a sine wave.

You have to be sure you use the correct sample rate and amplitude based on the settings you use. Also remember that sound files are not 0-(max), they are centered on 0.

[S.S.]

Sine-Wave is also ok.
Could you send me this vi, please?

Greetings




> I did this exact thing with a sine wave.
>
> You have to be sure you use the correct sample rate and amplitude
> based on the settings you use. Also remember that sound files are not
> 0-(max), they are centered on 0.

Message Edited by Support on 09-24-2008 03:55 PM

[Labviewguru]

It wouldn't be helpful to you if I sent the VI.

I started with "Multitone Waveform Example.vi" which I downloaded from NI's website.

I then altered the VI to generate tones in the dynamic range of the sound format I chose. In my case, I chose 8 bit stereo. I setup the VI to create a waveform with an amplitude of 255, however; this is centered about zero. 8 bit stereo requires a signal that is 0-255 (16 bit is centered about 0?). So all I did was to add 127.5 to the output of the waveform generator, and then create a 2D array by using the same waveform for each channel. I then put this waveform into the "Snd Write Waveform.vi" along with the appropriate format and other inputs.

If you have any specific questions, please feel free
to ask.

[S.S.]

> It wouldn't be helpful to you if I sent the VI.
Why not ? Please try it 😉 You can send it to my e-mail Adress of this
News-Mail.
>
> I started with "Multitone Waveform Example.vi" which I downloaded from
> NI's website.
I think this is standard in Labview 6
>
> I then altered the VI to generate tones in the dynamic range of the
> sound format I chose. In my case, I chose 8 bit stereo. I setup the
> VI to create a waveform with an amplitude of 255, however; this is
> centered about zero. 8 bit stereo requires a signal that is 0-255 (16
> bit is centered about 0?). So all I did was to add 127.5 to the
> output of the waveform generator, and then create a 2D array by using
> the same waveform for each channel. I then put this
waveform into the
> "Snd Write Waveform.vi" along with the appropriate format and other
> inputs.
I need 8 Bit Mono, because its only for driving a Motor. But 8 Bit Stereo is
also ok, because the second channel is not in use.

>
> If you have any specific questions, please feel free to ask.