i.MX ProcessorsのトピックRe: IMX.6UL ADC example program

IMX.6UL ADC example program

jonasnyberg — Thu, 22 Jun 2017 08:53:06 GMT

Hi all,

We have a project that involves reading one ADC channel at a maximum ~1KHz rate.

Does anyone know of any example C code for this that utilizes the VF610_adc.c driver directly?

What I've understood is that reading the in_voltageX_raw file directly from Linux is slow and takes up a lot of resources.

Kind regards,

Jonas

Re: IMX.6UL ADC example program

igorpadykov — Thu, 22 Jun 2017 10:37:42 GMT

Hi Jonas

please check FreeRTOS examples

Board Support Packages (7)
SDK2.2_iMX6UL_WIN(REV SDK2.2)
http://www.nxp.com/products/microcontrollers-and-processors/arm-processors/i.mx-processors/i.mx-6-processors/i.mx-6ultralite-processor-low-power-secure-arm-cortex-a7-core:i.MX6UL?tab=Design_Tools_Tab

Best regards
igor
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Re: IMX.6UL ADC example program

lategoodbye — Mon, 24 Jul 2017 18:10:32 GMT

Hi Jonas,

it's correct reading the raw ADC values via sysfs isn't efficient. In case you use a newer kernel there is also the IIO buffer and IIO trigger interface which may fits better.

Regards

Stefan

Re: IMX.6UL ADC example program

jonasnyberg — Tue, 25 Jul 2017 06:23:50 GMT

Hi Stefan,

Thanks for your reply. My kernel version is 4.1.15, do you have any idea if this is new enough?

Where do I find the IIO buffer and trigger and how do I read them?

Thanks in advance,

Jonas

Re: IMX.6UL ADC example program

lategoodbye — Wed, 26 Jul 2017 05:36:46 GMT

Yes, 4.1.15 should be sufficient. Please look at one of the many presentations about linux-iio. There are also example tools within the linux sources.