HI all,
I am trying to access the user leds in starter kit through following commands,
error getting as "resouce busy". when i try to export the pin 50 it works fine for export, unexport, change value, direction.
I am not able to export the pins of LED for usr.
there is no "value" file for thease LEDs.
Is it the case that i can not export them?
i was able to make the LED glow using Brightness file (brightness value other than 0).
Other thing how to set the super user in debug, when board is connected to pc thr ttyUSB1 interface.
error while setting the su mode.
please find the log file:
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| | _| .'| . | . | | __| _| . | | | -_| _| _|
|__|__|_| |__,|_ |___| |__| |_| |___|_| |___|___|_|
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Arago Project http://arago-project.org am335x-evm ttyO0
Arago 2013.12 am335x-evm ttyO0
am335x-evm login: root
root@am335x-evm:~# echo 36 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
root@am335x-evm:~# echo 50 > /sys/class/gpio/export
root@am335x-evm:~# echo "out" > /sys/class/gpio/gpio50/direction
root@am335x-evm:~# echo 1 > /sys/class/gpio/gpio50/value
root@am335x-evm:~# echo 0 > /sys/class/gpio/gpio50/value
root@am335x-evm:~# echo 37 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
root@am335x-evm:~# echo 38 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
root@am335x-evm:~# echo 39 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
root@am335x-evm:~# echo 50 > /sys/class/gpio/unexport
root@am335x-evm:~# cd ..
root@am335x-evm:/home# cd ..
root@am335x-evm:/# echo 38 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
root@am335x-evm:/# sudo echo 38 > /sys/class/gpio/export
-sh: sudo: command not found
root@am335x-evm:/# su echo 38 > /sys/class/gpio/export
Unknown id: echo
root@am335x-evm:/# su "echo 38 > /sys/class/gpio/export"
Unknown id: echo 38 > /sys/class/gpio/export
root@am335x-evm:/# cd sys
root@am335x-evm:/sys# cd class
root@am335x-evm:/sys/class# cd gpio
root@am335x-evm:/sys/class/gpio# echo 50 > /sys/class/gpio/export
root@am335x-evm:/sys/class/gpio# ls
export gpio50 gpiochip0 gpiochip32 gpiochip64 gpiochip96 unexport
root@am335x-evm:/sys/class/gpio# cd gpio50
root@am335x-evm:/sys/class/gpio/gpio50# ls
active_low direction edge power subsystem uevent value
root@am335x-evm:/sys/class/gpio/gpio50# echo direction
direction
root@am335x-evm:/sys/class/gpio/gpio50# cat direction
out
root@am335x-evm:/sys/class/gpio/gpio50# cat value
0
root@am335x-evm:/sys/class/gpio/gpio50# echo 1 > value
root@am335x-evm:/sys/class/gpio/gpio50# echo out > direction
root@am335x-evm:/sys/class/gpio/gpio50# cat direction
out
root@am335x-evm:/sys/class/gpio/gpio50# echo 0 > value
root@am335x-evm:/sys/class/gpio/gpio50# cat value
0
root@am335x-evm:/sys/class/gpio/gpio50# echo 1 > value
root@am335x-evm:/sys/class/gpio/gpio50# cat value
1
root@am335x-evm:/sys/class/gpio/gpio50# cd ..
root@am335x-evm:/sys/class/gpio# echo 36 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
root@am335x-evm:/sys/class/gpio# cd ..
root@am335x-evm:/sys/class# cd leds/
root@am335x-evm:/sys/class/leds# ls
evmsk:green:heartbeat evmsk:green:usr0
evmsk:green:mmc0 evmsk:green:usr1
root@am335x-evm:/sys/class/leds# cd evmsk\:green\:usr0
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# ls
brightness max_brightness subsystem uevent
device power trigger
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# cat max_brightness
255
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# cat brightness
0
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# echo 255 > brightness
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# echo 55 > brightness
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# echo 0 > brightness
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# cat trigger
[none] nand-disk timer oneshot heartbeat backlight gpio cpu0 default-on mmc0
root@am335x-evm:/sys/class/leds/evmsk:green:usr0# cd ..
root@am335x-evm:/sys/class/leds# cd evmsk\:green\:usr1
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# ls
brightness max_brightness subsystem uevent
device power trigger
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# cat brightness
0
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# echo 20 > brightness
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# echo 255 > brightness
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# echo 0 > brightness
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# cat trigger
[none] nand-disk timer oneshot heartbeat backlight gpio cpu0 default-on mmc0
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# cd ..
root@am335x-evm:/sys/class/leds# ls
evmsk:green:heartbeat evmsk:green:usr0
evmsk:green:mmc0 evmsk:green:usr1
root@am335x-evm:/sys/class/leds# cd evmsk\:green\:heartbeat
root@am335x-evm:/sys/class/leds/evmsk:green:heartbeat# ls
brightness max_brightness subsystem uevent
device power trigger
root@am335x-evm:/sys/class/leds/evmsk:green:heartbeat# cat trigger
none nand-disk timer oneshot [heartbeat] backlight gpio cpu0 default-on mmc0
root@am335x-evm:/sys/class/leds/evmsk:green:heartbeat# cd ..
root@am335x-evm:/sys/class/leds# ls
evmsk:green:heartbeat evmsk:green:usr0
evmsk:green:mmc0 evmsk:green:usr1
root@am335x-evm:/sys/class/leds# cd evmsk\:green\:usr1
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# ls
brightness max_brightness subsystem uevent
device power trigger
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# cat trigger
[none] nand-disk timer oneshot heartbeat backlight gpio cpu0 default-on mmc0
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# echo gpio > trigger
root@am335x-evm:/sys/class/leds/evmsk:green:usr1# cat trigger
none nand-disk timer oneshot heartbeat backlight [gpio] cpu0 default-on mmc0
root@am335x-evm:/sys/class/gpio# echo 37 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
