Power down the BeagleBone Black using the on board power button

The beaglebone black board has a power button next to the RJ45 ethernet connector. Pressing that button can get the board to cleanly shutdown.

First install acpid:

root@beagle1:/home/james# apt-get install acpid

Now test the shutdown. Press the Power button:

root@beagle1:/home/james#
Broadcast message from root@beagle1 (Fri Sep 27 01:13:49 2013):

Power button pressed
The system is going down for system halt NOW!
Connection to 192.168.1.116 closed by remote host.
Connection to 192.168.1.116 closed.

Installed system was Debian 7.1

james@beagle1:~$ more /etc/debian_version 
7.1
james@beagle1:~$ uname -a
Linux beagle1 3.8.13-bone26 #1 SMP Fri Aug 16 20:56:24 UTC 2013 armv7l GNU/Linux

Enable UART5 on beagle bone running debian

First mount debugfs:
mount -t debugfs none /sys/kernel/debug

Enable UART5:
echo 24 > /sys/kernel/debug/omap_mux/lcd_data9
echo 4 > /sys/kernel/debug/omap_mux/lcd_data8

Hardware Pins:
P8: 37 UART5_TXD
P8: 38 UART5_RXD

Device to access:
/dev/ttyO5

References:
http://www.jerome-bernard.com/blog/2012/06/04/beaglebone-serial-ports-and-xbees/