JGeo wrote:Otherwise, I can reboot the EV3 from the command line, but I can not shut it down with for example "root@EV3:~# shutdown -P -t 0 now". What would be the command?
"halt -p" works for me, using the latest lejos fs image.
It is possible to use buttons for this, but you'll need to write a script which monitors them, detect a long push (for instance 4 secs) and then issues the halt command. Just start it with an init script and it will do its job.
I've done something similar for a headless Raspberry Pi. If it can help, here
is an article explaining how. You'll not be able to directly use it as is since i's written in Python and uses RasPi GPIOs, but the same job can be easily transposed using /dev/lm_xx stuff and sh.
The article is written in French, but maybe Google translate can help, and otherwise feel free to ask.