PROCESSOR-SDK-AM335X: ADC buffer enable fails

ANEESHYA ROSE K M

Prodigy 120 points

Part Number: PROCESSOR-SDK-AM335X

To enable continuous mode adc in AM3354BZCZ80 I tried to do the following

echo 1 > /sys/bus/iio/devices/iio\:device0/scan_elements/in_voltage7_en

echo 100 > /sys/bus/iio/devices/iio\:device0/buffer/length

echo 1 > /sys/bus/iio/devices/iio\:device0/buffer/enable

But the third command threw an error as buffer not started buffer parameter update failed (-22)

How can this error be solved? The driver included is TI's AM335X ADC driver

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

What is the Linux version you use? Is the ADC configured correctly? See processors.wiki.ti.com/.../Linux_Core_ADC_Users_Guide for details.

0 ANEESHYA ROSE K M over 8 years ago in reply to Biser Gatchev-XID

Prodigy 120 points

linux version : 3.12.30-AM335x-PD15.2.2

ADC was configured as per http://processors.wiki.ti.com/index.php/Linux_Core_ADC_Users_Guide

And in one shot mode we are able to read the channel value. But in continuous mode, this problem arises.

0 ANEESHYA ROSE K M over 8 years ago in reply to ANEESHYA ROSE K M

Prodigy 120 points

I have'nt done anything. But now I am getting an error : -sh: echo: write error: Invalid argument
!

It is able to write 0 but not able to write 1.

echo 1 > /sys/bus/iio/devices/iio\:device0/buffer/enable --> This command gives error as -sh: echo: write error: Invalid argument

but,

echo 0 > /sys/bus/iio/devices/iio\:device0/buffer/enable does'nt throw any error. Why is it happening?

0 Biser Gatchev-XID over 8 years ago in reply to ANEESHYA ROSE K M

TI__Guru**** 393215 points

The Linux version you use is quite old and may not support fully the buffer feature. The ADC wiki information is valid for the Linux Processor SDK: www.ti.com/.../PROCESSOR-SDK-AM335X

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PROCESSOR-SDK-AM335X: ADC buffer enable fails