Serial communication permissions Nitrogen 6x Android 7.1

[jonathan_nisbet]

I am trying to configure a Nitrogen 6x board (uses i.MX6 quad processor) running Android 7.1 to communicate with another board via Serial Port.  I am getting a permission denied error within the application I am testing when it tries to initialize the port for communication.  I am trying to use /dev/ttymxc0 as the port for this.  I used adb to see what permissions were defined for that path and was presented with the following:

I tried to modify the permissions to allow root to read and write from the port but received a read-only file system error when trying to do so.  Is this an issue that anyone has seen before?  If so, would it be possible to get some help in order try and resolve this?

[gusarambula]

Hello Jonathan Nisbet,

This may be related to the way Android handles permissions. There is no much information regarding this on the i.MX documentation as it is dependent on the Android version you are using. I would recommend reviewing Google's Android documentation and Developer's forums.

Have you tested using a debug image to see if this level of access allows you to access the serial port? I’m not familiar with the Nitrogen Android BSP but it would be worth testing if the option is available.

Regards,