I would like to write a Java-App that controls GPIO-pins (on the DragonBoard). First I tried to do it via Java directly (executing shell-commands and accessing the sysfs-files via the File libraries). It seems like the App never got enough permissions, so I tried it via the NDK and the libsoc library as described in http://www.96boards.org/blog/access-gpio-pins-programmatically/).
Unfortunately, this doesn’t work either, the open(path, flags) function with path="/sys/class/gpio/export" and flags=1052673 in file.c on line 9 got me fd=-1;
Could someone please help me with that?