Generate Sine Wave through DAC using DMA ping pong buffers in FRDM k64 using MQX

[oliviachristyva]

Hi guys,

I have a code which generate a perfect audio output through DAC using DMA  ping pong buffers. But now I want to generate a stable sine wave using this same DMA ping pong buffer. I tried with the audio code but failed. he sine wave is not continuously coming on the scope . Is it possible to use this same audio code to generate a sine wave or do I have to write another code for that.

If it possible to use the Audio code for generating sine wave what changes should I make in the code.

I am writing the code in MQX 4.2

please help

regards,

Olivia

[oliviachristyva]

Hi  Daniel,

Thank you for your suggestions. i finally got it working with some changes in the audio dma code.

Regards,

Olivia 

[danielchen]

Hi Olivia:

I would suggest your refer to the following application note, it maybe helpful. In this application note, DMA and interrupt based ping-pong buffer scheme is discussed.

http://cache.nxp.com/assets/documents/data/en/application-notes/AN4520.pdf?fsrch=1&sr=1&pageNum=1 

http://cache.nxp.com/assets/documents/data/en/application-notes/AN4800.pdf?fsrch=1&sr=2&pageNum=1 

Regards

Daniel