Control the on-board LED on Raspberry Pi

There are 5 on-board LEDs on Raspberry Pi. One of them (marked OK or ACT) can be programmed as GPIO. It's connected GPIO16, usually SD card access indicator.

by default, it is set triggered by mmc0. It can be checked with the command:

# cat /sys/class/leds/led0/trigger
none [mmc0] timer oneshot heartbeat backlight gpio cpu0 default-on

In order to program it as GPIO, remove the trigger with the command:
# echo none >/sys/class/leds/led0/trigger

Then, to turn on the LED, enter the command:
# echo 1 >/sys/class/leds/led0/brightness

Then, to turn off the LED, enter the command:
# echo 0 >/sys/class/leds/led0/brightness

After that, resume the trigger by mmc0 with command (or reboot):
# echo mmc0 >/sys/class/leds/led0/trigger

Control the on-board LED on Raspberry Pi

In my experience, it cannot be perform using sudo, you have to login as root. To login as root, refer to last post "Set password of root".

Related:

• Control the on-board LED using Python
• Python/RPi.GPIO Control Raspberry Pi 2 B on-board ACT LED
• Python control Raspberry Pi 2 PWR/ACT LED, using RPi.GPIO or system's shell
• Control the on-board LED using C language