MQX Software SolutionsのトピックRe: Generate Sine Wave through DAC using DMA ping pong buffers in FRDM k64 using MQX

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

oliviachristyva — Wed, 01 Mar 2017 07:29:35 GMT

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

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

danielchen — Tue, 11 Apr 2017 07:17:53 GMT

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

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

oliviachristyva — Tue, 11 Apr 2017 12:44:16 GMT

Hi Daniel,

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

Regards,

Olivia