topic Storing ADC data in DMA in Kinetis Microcontrollers

Storing ADC data in DMA

notanivipul — Tue, 15 Jun 2021 07:55:55 GMT

Hello,

I am using FRDM-KW38 development board for one of my projects. I am using 2 ADC channels to read analog data. I want to read from one channel and store the data in DMA. After it is done I want to read data from the other channel and parallelly perform operations on the data stored in DMA from ADC channel 1.

I am learning about DMAs for the first time. Can anyone help me with my problem.

Best regards,

Vipul

Re: Storing ADC data in DMA

nxf56274 — Wed, 16 Jun 2021 08:10:07 GMT

Hi,

What is the parallel operations you need to do? DMA can be used to move the data from A to B without the CPU involved. You can't read the data from channel 1 and deal with the data from channel 2 at the same time.

Have a great day,
TIC

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Re: Storing ADC data in DMA

notanivipul — Wed, 16 Jun 2021 08:32:59 GMT

Hi @nxf56274

Maybe I phrased it wrong, I want to collect the ADC data in DMA channel 1 and when the channel is full, I want to transfer the data to memory to perform FFT. While performing FFT I want the next set of data from the ADC to be stored in DMA.

Best regards,

Vipul

Re: Storing ADC data in DMA

nxf56274 — Thu, 17 Jun 2021 08:48:29 GMT

Hi,

Our adc example has the dma function. The example uses a flag to check if the dam transfer is complete. You can also check this flag. When the flag is set, you can perform FFT and start the second transfer.

Have a great day,
TIC

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Re: Storing ADC data in DMA

notanivipul — Mon, 21 Jun 2021 05:57:59 GMT

Hi @nxf56274

Thanks for the reply.

Could you please guide me with the example code, I am not able to follow it - like I am not able to find the DMA function and what parameters are to be changed to make it functional.

Best Regards,

Vipul

Re: Storing ADC data in DMA

nxf56274 — Mon, 21 Jun 2021 06:18:52 GMT

Hi,

I check the frdm-kw38 sdk. It doesn't have the adc dma example. But you can refer frdm-kl43z adc example. They have the similar architecture.

Have a great day,
TIC

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