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Karg
05-10-2016, 08:04 PM
Hello all,

I have an audio shield for my Teensy, and I am wondering if there is a possibility to pass the analog signal from the line input directly to the ouput.
What I basically want is to "sneak into" the audio signal in the way that I typically do not alter the music at all, while being able to record and playback parts on demand.

Is there a good way to achieve that?

Thanks a lot in advance!

Best,
Karg

WMXZ
05-10-2016, 08:18 PM
Hello all,

I have an audio shield for my Teensy, and I am wondering if there is a possibility to pass the analog signal from the line input directly to the ouput.
What I basically want is to "sneak into" the audio signal in the way that I typically do not alter the music at all, while being able to record and playback parts on demand.

Is there a good way to achieve that?

Thanks a lot in advance!

Best,
Karg

are you aware of the gui https://www.pjrc.com/teensy/gui/ ?

Karg
05-10-2016, 08:32 PM
Yes, I guess I was unclear in my question, so allow me to rephrase:

If I connect the line input with the line output through the audio library, is my audio signal AD converted when coming in and DA converted when getting sent out again, or will it be a direct analog connection between in and out?

I would like to hijack the signal path of an analog device, and spike in samples every now and then without compromising the analog signal... Is that possible?

WMXZ
05-10-2016, 08:45 PM
Yes, I guess I was unclear in my question, so allow me to rephrase:

If I connect the line input with the line output through the audio library, is my audio signal AD converted when coming in and DA converted when getting sent out again, or will it be a direct analog connection between in and out?

I would like to hijack the signal path of an analog device, and spike in samples every now and then without compromising the analog signal... Is that possible?

I'm not sure if this helps, but https://www.pjrc.com/teensy/SGTL5000.pdf figure 2 gives the simplified internal structure of the CODEC.

However, the audio library makes only sense if the path is via local (digital) buffers

but outside the audio library, you could play with directly controlling the SGTL5000 and generate novel effects.