Generating custom wave forms.

[chinoy]

So for years I managed with a cheap USB Sound card. And windows software to output any kind of signal I want.
Latter the same USB sound card started to work with android.
This worked well for years.
It allowed you to pick the shape of the wave form you want i.e. square / sawtooth etc. it allowed you to pick the freq you want.
And the voltage as long as it was under 5 volts.

But what if I want to put out customised wave forms. Say I want a sine wave with a nipple projection on each end.
How would one achieve this.

Preferably without having to invest a few thousand dollars in a high end function generator.
I vaguely remember one of the s/w allowed you to code a custom wave form. But cant remember the name.

More recently I found a blue tooth board with built in amp. In normal mode it works like a blue tooth receiver but if you plug in a USB port it become a sound card. Its like 2-3$. And by using the inbuilt AMP or an external amp you can boost your voltage output as high as you want.
Some software even allow you to inject noise into your signal.
It would be nice if there was a post linking all the PC based. s/w which allows you to use your sound card as a scope or as a function generator. Back in the day we would hook up the mic to probes and use it as a cheap scope. PC scope was a popular s/w back then.
Worst case I am thinking of doing a pic or arduino project that allows one to output custom wave forms. 

[mikerj]

The phrase you should be looking for is "arbitrary waveform generator".  Pretty sure you could do this with Scilab (https://www.scilab.org/) though this is primarily a powerful numeric analysis and data visualisation tool (a kind of open source Matlab) so don't expect some knobs and button to twiddle, you would generate the waveform with math functions which can then be sent to the audio output.

[NiHaoMike]

It would be nice if there was a post linking all the PC based. s/w which allows you to use your sound card as a scope or as a function generator. Back in the day we would hook up the mic to probes and use it as a cheap scope. PC scope was a popular s/w back then.

Try baudline. http://baudline.com/