/dev/i2c-x permission

[davorin]

Evenin' (o;

What is the command to make changes to /dev/i2c-X persistent?

After every reboot the permission is reset to 660.
And adding user snmp to group i2c doesn't help either to use an external command reading i2c bus.

[M33P]

http://www.reactivated.net/writing_udev ... #ownership

Udev controls the creation of /dev/ nodes each boot.

Udev rules also control what permissions etc they are created with - you can change the group to a suitable one or change permissions to allow read/write to everyone.

[JPB-HK]

This took a little searching as a noob to Linux for me to get this working. But here is what I did.

edited the 60-ic2-tools.rules file:

Code: Select all

   sudo nano /lib/udev/rules.d/60-i2c-tools.rules

I seperated out the i2c-0 so it remained MODE 0660, here are the two lines:

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KERNEL=="i2c-0"     , GROUP="i2c", MODE="0660"
KERNEL=="i2c-[1-9]*", GROUP="i2c", MODE="0666"

I rebooted, and the permissions changed to:

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crw-rw---T 1 root i2c 89, 0 Dec 19 21:01 /dev/i2c-0
crw-rw-rwT 1 root i2c 89, 1 Dec 19 21:01 /dev/i2c-1

As soon as I get back to my Raspberry Pi with an I2C device, I can confirm this.
Hope this helps.
John

[yvanttt]

Thank you that worked on Pidora with a model B+