How to turn off blue led or green led under armbian system

#1

ROCK3 Model A
OS: Armbian (23.02.2)
Kernel: 6.1.11

#2

I’ve been experimenting with led’s on the ROCK 3A.

The schematic shows the Green and Blue LED’s on page 26:

The green LED is permanently connected to 3V3 so it is controlled by the power supply being on or off. You could remove the 4k7 resistor to permanently turn it off or add a 200R resistor and then control it with GPIO0_C6

The blue led is controlled by GPIO0_B6 so you can turn this off in software.

One way of doing it is to write an overlay that will turn off the led by setting the trigger to “none”. This overlay runs the heartbeat on the blue led to give you a clue - hint read the comments in the original:

You will need to turn the led off before the armbian-led-state.service runs or disable the service.

Or you could just do:
sudo bash -c “echo none > /sys/class/leds/blue:heartbeat/trigger”

Then the armbian-led-state.service will save the state for next boot.

#3

Or very much easier:

  1. STOP the ‘armbian-led-state.service’ by running the command
    sudo systemctl stop armbian-led-state.service
  2. EDIT the config file ‘/etc/armbian-leds.conf’
    sudo vi /etc/armbian-leds.conf
    Change the value for the entity ‘trigger’ of section ‘[/sys/class/leds/blue:heartbeat]’ to ‘none’ so it looks like this:
    [/sys/class/leds/blue:heartbeat]
    trigger=none
    brightness=0
  3. START the ‘armbian-led-state.service’ again by running the command
    sudo systemctl start armbian-led-state.service

Voila, done!

Advantage:
while the system is starting, the BLUE LED keeps its pervious function to show you that
a) a boot-volume was found (led is lit up)
b) the system is starting up (led flashes, like heartbeat)
c) the service started reading the new config (==> the led is dark, stops flashing)

This is exactly what I want :slight_smile: