Is there an example showing USB audio with eDMA and I2S?

[donturner]

I'm developing a USB audio interface with a FRDM-K66F board and KSDK 2.x. Just reading the documentation here: http://cache.freescale.com/files/training/Enhanced-Direct-Memory-Access-Controller-Training.pdf 

It includes an example for an "Audio equalizer". Is there any source code with this example? It'd be extremely useful to me in development.

Alternatively, are there any examples which show how to set up the DMA controller for USB to SAI peripheral using ping-pong buffers? 

Many thanks, Don

[xiangjun_rong]

Hi, Don,

Unfortunately, we have not the USB audio speaker example with equalizer function. But I think you can use USB speaker  examples to implement the function.

1)We have USB device speaker in SDK2.0, pls refer to the example.

C:\DriverE\Freescale\SDK2.0_K26\boards\frdmk66f\usb_examples\usb_host_audio_speaker\freertos\kds

2)regarding the equalizer, the equalzer is multiple band-pass digital filtering, you can use either FIR or IIR to implement it. I attach an application note about the equalizer, although it is based on DSP56300, it is helpful to understand the equalizer. In SDK2.0, we have developed the FIR and IIR api function, Kinetis use core to do FIR/IIR.

Hope it can help you

BR

Xiangjun Rong