How to : Disable BeagleBone USR Heartbeat LED lights

The BeagleBone Black by default has 4 User LED's USR0, USR1, USR2 and USR3 that light up to show the board is alive. While useful it can be annoying.

There are 4 sub directories under /sys/class/leds which allow you to configure the LED behaviour. There is one directory per LED. Within each sub directory a trigger file details what triggers the LED e.g.

# cat /sys/class/leds/beaglebone\:green\:usr0/trigger

none nand-disk mmc0 mmc1 timer oneshot [heartbeat] backlight gpio cpu0 default-on transient

The [heartbeat] is what is showing the board is alive. This can be disabled via :

# echo none > /sys/class/leds/beaglebone\:green\:usr0/trigger

# echo none > /sys/class/leds/beaglebone\:green\:usr1/trigger

# echo none > /sys/class/leds/beaglebone\:green\:usr2/trigger

# echo none > /sys/class/leds/beaglebone\:green\:usr3/trigger

To light up the LED use the brightness file.

Turn USR0 on

# echo 1 > /sys/class/leds/beaglebone\:green\:usr0/brightness

Turn USR0 off

# echo 0 > /sys/class/leds/beaglebone\:green\:usr0/brightness

Reboot

The LEDs will be reset on after reboot which is useful for troubleshooting. The /sys directory on Linux is a RAM based File system. For ease you could create a simple bash script to run as the last file on boot.

# cat DisableUSRLEDs.sh

#!/bin/bash

echo none > /sys/class/leds/beaglebone\:green\:usr0/trigger

echo none > /sys/class/leds/beaglebone\:green\:usr1/trigger

echo none > /sys/class/leds/beaglebone\:green\:usr2/trigger

echo none > /sys/class/leds/beaglebone\:green\:usr3/trigger