LED Configuration

The LED configuration is located in system uci subsystem, and written in the /etc/config/system file.

Basic led configuration is available via LuCI on the System > LED Configuration page.

The led section contains settings that apply to non-default leds.
Default leds are usually power on, ethernet port activity, usb port activity, and wifi radio activity.

This is an example of leds on a tp-link router with usb port.

root@lede:/# uci show system | grep "system.led"
system.led_usb=led
system.led_usb.name='USB'
system.led_usb.sysfs='tp-link:green:usb'
system.led_usb.trigger='usbdev'
system.led_usb.interval='50'
system.led_usb.dev='1-1'
system.led_wlan=led
system.led_wlan.name='WLAN'
system.led_wlan.sysfs='tp-link:green:wlan'
system.led_wlan.trigger='phy0tpt'

root@lede:/# cat /etc/config/system
config led 'led_usb'
        option name 'USB'
        option sysfs 'tp-link:green:usb'
        option trigger 'usbdev'
        option interval '50'
        option dev '1-1'

config led 'led_wlan'
        option name 'WLAN'
        option sysfs 'tp-link:green:wlan'
        option trigger 'phy0tpt'

All LEDs are represented by entries in the sys filesystem. You can check which LEDs are available in the /sys/class/leds directory.

The name of an entry typically consists of the name of the hardware providing the LED (the router model), the color of the LED, and it’s designation (usually the label on the case).
Some LEDs can show different colors. In this case, you will find one entry per color.

root@lede:/# ls /sys/class/leds/
tp-link:green:qss     tp-link:green:usb
tp-link:green:system  tp-link:green:wlan

The LED can be controlled by various events in the system, which is selected by the trigger option. Depending on the trigger, additional options must be specified. First of all, you need to know which triggers are available for a led, to do that simply look at the trigger file of that led. Example:

root@lede:/# cat /sys/class/leds/tp-link:green:qss/trigger
[none] switch0 timer default-on netdev usbdev phy0rx phy0tx phy0assoc phy0radio phy0tpt 

If we wanted to (temporarily) assign a default-on trigger to the led, we would write

root@lede: echo "default-on" > /sys/class/leds/tp-link:green:qss/trigger

You can confirm that you changed this by using cat again, you will see it has changed and the selected trigger is highlighted.

root@lede:/# cat /sys/class/leds/tp-link:green:qss/trigger
none switch0 timer [default-on] netdev usbdev phy0rx phy0tx phy0assoc phy0radio phy0tpt 

Now, this change will be lost on reboot, if you want to make a permanent change, you need to add the trigger in uci configuration.

If you have already a section in uci configuration that shows the led you want to set up, you just need to add the trigger.

For example, if you want change the trigger assigned to tp-link:green:wlan into “default-on” and you already have a block of options for it like this when you write uci show system | grep “system.led” (you can have more or less, it may also not have a trigger already assigned).

system.led_wlan=led
system.led_wlan.name='WLAN'
system.led_wlan.sysfs='tp-link:green:wlan'
system.led_wlan.trigger='phy0tpt'

then you can write

uci set system.led_wlan.trigger='default-on'
uci commit

If you don't have any configuration for it, you can add it and the trigger by editing the following example text (that sets wps led as “default-on” and then copy-pasting it whole in the terminal window.

rule_name=$(uci add system led_wps) 
uci batch <<EOF set system.$rule_name.name='WPS'
set system.$rule_name.sysfs='tp-link:green:wps'
set system.$rule_name.trigger='default-on'
EOF
uci commit

You can confirm the changes by running service led restart.

Now we explain in detail what each trigger does.

The LED is always in default state. Unlisted LEDs are default OFF, so this is only useful to declare an LED to be always ON.

The LED is on if a link on one of the configured switch ports is established.

Consider for example a port_mask of 0x1e, which is 00011110 in binary. From right to left, this excludes CPU, includes four switch ports and sets the remaining bits to 0 to exclude further ports (e.g. because there are no more physical ports).

speed_mask assigns a bit for standard BASE-T speeds. With this it's possible to trigger an LED only on specific speeds, for example amber for 100mbps and green for gigabit.

Bit assignments for speed_mask are as follows:

• [0] 0x01 - Unknown speed or cable/link problem
• [1] 0x02 - 10BASE-T
• [2] 0x04 - 100BASE-T
• [3] 0x08 - 1000BASE-T
• bits 4-7 reserved for future expansion and dont do anything.

For example a speed_mask of 0x0C, which is 00001100 in binary, will only trigger the LED when the speed is 100BASE-T or 1000BASE-T. We can then apply the inverse 0x03 (binary 00000011) to another LED, effectively getting different colors/leds to flash depending on the connection speed.

The LED blinks with the configured on/off frequency.
If not installed already, install it with:

root@lede:/# opkg install kmod-ledtrig-timer

The LED is ON. Deprecated, use default=1 trigger=none instead. If not installed already, install it with:

root@lede:/# opkg install kmod-ledtrig-default-on 

The LED flashes to simulate actual heart beat thump-thump-pause. The frequency is in direct proportion to 1-minute average CPU load. If not installed already, install it with:

root@lede:/# opkg install kmod-ledtrig-heartbeat

The LED flashes as data is written to flash memory.

The LED flashes with link status and/or send and receive activity on the configured interface. If not installed already, install it with:

root@lede:/# opkg install kmod-ledtrig-netdev

The LED flashes on events triggered in physical interface, rather than in software network interface. Besides phy triggers have more events, it also provides possibility of static LED setup in case you want to monitor your 2.4 GHz radio (phy0 usually) and 5 GHz radio (phy1 usually) separately. netdev can’t guarantee this distinguishing since wlan0 may be referring to 2.4 GHz or 5 GHz radio based on current network setup.

• phy0rx - flashes on reception.
• phy0tx - flashes on transmission.
• phy0assoc - flashes on client association.
• phy0radio - (unknown, this option did nothing on my tl-wr1043nd)
• phy0tpt - flashes slowly and steadily on network activity.in comparison to energetic flashes of tx and rx modes

The LED turns ON if USB device is connected. If not installed already, install it with:

root@lede:/# opkg install kmod-ledtrig-usbdev 

To find out device name use logread to search for it or list /sys/bus/usb/devices (for this example, there would be /sys/bus/usb/devices/1-1 device).
Within lets say /sys/bus/usb/devices/1-1, you should have a manufacturer and product files, simply use cat to reveal their contents, which will help identify the device.

Allows LEDs to be controlled by gpio events. If not installed already, install it with:

root@lede:/# opkg install kmod-ledtrig-gpio

Flash LEDs when a particular packets passing through your machine. If not installed already, install it with:

root@lede:/# opkg install kmod-ipt-led

According to this, the package was named kmod-ledtrig-netfilter in older versions

For example to create an LED trigger for incoming SSH traffic:

root@lede:/# iptables -A INPUT -p tcp --dport 22 -j LED --led-trigger-id ssh --led-delay 1000

Then attach the new trigger to an LED on your system:

root@lede:/# echo netfilter-ssh > /sys/class/leds/<ledname>/trigger 

Please remember to change the sysfs option to LEDs that are actually present on your router.
This can be done easily through LuCI. Following examples are from /etc/config/system file:

config 'led'
	option 'sysfs'		'wrt160nl:amber:wps'
	option 'trigger'	'heartbeat'

config 'led' 'wlan_led'
	option 'name'           'WLAN'
	option 'sysfs'          'tl-wr1043nd:green:wlan'
	option 'trigger'        'netdev'
	option 'dev'            'wlan0'
	option 'mode'           'link tx rx'

This led lights up when an USB-dongle properly registers with the 3G/EDGE/GPRS network.

config 'led'
	option 'name'           '3G'
	option 'sysfs'          'asus:blue:3g'
	option 'trigger'        'netdev'
	option 'dev'            '3g-wan'
	option 'mode'           'link'

config 'led'
	option 'sysfs'		'wrt160nl:blue:wps'
	option 'trigger'	'timer'
	option 'delayon'	'500'
	option 'delayoff'	'2000'