Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 2 of 2

Thread: Analog Input and Output DMA

  1. #1

    Analog Input and Output DMA

    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.

  2. #2
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    24,783
    Quote Originally Posted by Demolishun View Post
    - 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....

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •