Beagle Bone black debain gpio access denied

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1

Hello,

Yet another newbie question.

I have got latest debian image on my beagle bone black.
uname - r output: 4.9.45-ti-r57

and I noticed various gpio directory in /sys/class/gpio

when I tried
echo 69 > unexport
it gave me permission denied.
so I changed the permission of unexport file to be 666

and now when I try to use the same command it gives me an error:
-bash: echo: write error: Invalid argument

Can anyone please help…

Ultimately I want to develop a C++ project to toggle LED which is connected to one of the pins…

Any help regarding this matter is deeply appreciated.

Regards,
Hemant Kapoor

2

Switching to root before doing sysfs operations, (e.g. sudo su), typically seems to work for me…

3

Hello,

Thanks for the response…

I did manage to sort the issue by performing two steps:

a. Added a udev rule to make gpio accessible
b. Added user to gpio group…

Regards,
Hemant Kapoor