Analog Input and Output DMA

[Demolishun]

Board: Teensy 3.1
Libraries: 1.19

Okay, I really like the audio libraries so far. Really nice and simple. However, when I tried to use multiple Analog inputs I get issues like the chip is wandering off somewhere. I looked at the Analog input library and it looks like it assumes a specific DMA for that object. This is fixed in the library and is not a parameter. So this means I can have only one Analog audio input channel via that object.

This is not for an audio solution, but I really like how you handle analog in general in the audio library. So it is more of a generic do DMA input on multiple analog inputs kind of approach I want.

So this brings me to the question:
- Will the libraries change this behavior in the future? Or should I look into writing my own version of the Analog input objects for the audio?
- Is there a list somewhere of the DMAs in use in each library so I can prevent walking on other libs that use DMA? This would be if I make a custom Analog audio object to handle multiple DMA analog inputs.

I think the audio library has the potential to be a generic analog input filtering code base for doing all kinds of analysis. Regardless if this is for audio or other applications. That is why I want this to work! If interested I could share my objects if I need to go that route.

 

[PaulStoffregen]

- Will the libraries change this behavior in the future?

Probably, but it's not high on my priority list, so for the near term, it'll probably only change when/if someone implements other ADC input objects and submits a patch or pull request.

Or should I look into writing my own version of the Analog input objects for the audio?

Yes. If you make something useful, I hope you'll consider contributing it.

- Is there a list somewhere of the DMAs in use in each library so I can prevent walking on other libs that use DMA? This would be if I make a custom Analog audio object to handle multiple DMA analog inputs.

Yes. A new DMAChannel class was added in 1.20-rc1. So far, none of the libraries actually use it yet, but I'm planning to update them soon. But "soon" is relative....