Generating sin/square waves sound

[Dave Angel]

On 12/30/2011 02:17 AM, Paulo da Silva wrote:
> Hi,
> Sorry if this is a FAQ, but I have googled and didn't find any
> satisfatory answer.
>
> Is there a simple way, preferably multiplataform (or linux), of
> generating sinusoidal/square waves sound in python?
>
> Thanks for any answers/suggestions.
If you're willing to be Linux-only, then I believe you can do it without 
any extra libraries.

You build up a string (8 bit char, on Python 2.x)  of samples, and write 
it to  "/dev/audio".  When i experimented, I was only interested in a 
few seconds, so a single write was all I needed.

Note that the samples are 8 bits, and they are offset by 128.  So a zero 
signal would be a string of 128 values.  A very quiet square wave might 
be a bunch of 126, followed by a bunch of 130.  and so on.  And the 
loudest might be a bunch of 2's followed by a bunch of 253's.

You'll have to experiment with data rate;   The data is sent out at a 
constant rate from your string, but I don't know what that rate is.


-- 

DaveA