[Health] [sugar] generate clean tone to speakers (first prototype of working EKG around the XO )

[Bert Freudenberg]

Also, any Etoys object has a "play frequency of ..." command (in the  
viewer's "sound" category) that plays a sine wave of that frequency.  
This uses Squeak's FM synthesis and outputs to ALSA directly with no  
involvement of gstreamer or csound.

- Bert -

On 02.04.2008, at 13:25, Walter Bender wrote:
> there is a simple example in Pippy as well.
>
> -walter
>
> On Wed, Apr 2, 2008 at 1:14 AM, Arjun Sarwal <arjun at laptop.org> wrote:
>> Tom,
>>
>>>
>>> Arjun, could you suggest an activity that gives a good clean  
>>> example of
>>> sending sound to the speakers? Thanks.
>>>
>>>
>> You could use gstreamer (the same package the measure uses to grab  
>> audio data)
>> to create a pipeline, a command line example is below which generates
>> a sine of 500Hz
>>
>>  gst-launch-0.10 audiotestsrc wave=sine freq=500 ! audioconvert !  
>> alsasink
>>
>> In python you could create a pipeline and implement it similar lines
>> to that given in audiograb.py in the Measure code.
>>
>>
>> I think it is possible to generate tones using Csound too and perhaps
>> other Activities are doing it, but I'm not aware of them.
>>
>>
>> regards
>> Arjun
>>
>> ---
>> Arjun Sarwal
>> Intern at One Laptop per Child
>> <arjun at laptop.org>
>> http://laptop.org/
>>