You are looking at an old revision of the page Devices-Overview. This revision was created by Nikolaus Schaller.
How to control Devices from user space (command line)
Introduction
This page lists the most important devices and drivers that are specific to this board. And how they can be accessed from user space.
For the Angstrom Image, we have predefined symbolic links in /dev/platform
Touch Screen
is mapped to
/dev/input/touchscreen
pen down status can be read through
cat /sys/devices/virtual/gpio/gpio157/value
LCD
can be selected by adding "omapdss.def_disp=lcd" to the boot args. This is done by "setenv defaultdisplay lcd " in our boot.scr.
choose from user space by ???
To disable/enable (power down/up) the LCD (state=0: off, state=1: on)
echo "$state" >/sys/devices/omapdss/display2/enabled
DVI
can be selected by adding "omapdss.def_disp=dvi" to the boot args
power (state=0: off, state=1: on)
echo $state >/sys/devices/virtual/gpio/gpio170/value
S-Video
can be selected by adding "omapdss.def_disp=venc" to the boot args
Backlight
power (state=0: off, state=1: on)
echo $state >/sys/devices/virtual/gpio/gpio145/value
GPS
power (state=0: off, state=1: on) - you may have to switch on/off/on to reset the GPS chip
echo $state >/sys/devices/virtual/gpio/gpio156/value
device file (use 9600 baud)
cat /dev/ttyS1
if the external antenna is active can be determined through
cat /sys/devices/virtual/gpio/gpio138/value # 1=ext. ant.
AUX and Power button
button status can be read through
cat /sys/devices/virtual/gpio/gpio136/value # 0=AUX pressed
cat /sys/devices/virtual/gpio/gpio137/value # 0=POWER pressed
LEDs are switched through
echo $state >/sys/devices/virtual/gpio/gpio70/value # AUX - red
echo $state >/sys/devices/virtual/gpio/gpio71/value # AUX - green
echo $state >/sys/devices/virtual/gpio/gpio78/value # POWER - red
echo $state >/sys/devices/virtual/gpio/gpio79/value # POWER - green