Wifi LED blinking

Products Support DragonBoard410c
#1

Hi!

My Dragonboard 410c wifi led is blinking (green light), probably to indicate when the wifi is working.

How to I turn it off, while leaving the wifi functionality on (as it is)? The product that I’m working on requires no blinking lights.

I want to change my default device-tree, can I boot image with separate device tree binary?
#2

Several possibilities:

a. You can remove the led (led@5) default trigger from the device tree (apq8016-sbc.dtsi) and rebuild your kernel image.

b. At runtime, on your board you can also use dt-update tool:

git clone https://github.com/96boards/dt-update.git
cd dt-update/
make && make install
dbootimg /dev/disk/by-partlabel/boot -x dtb | dtbtool -n led@5 -s linux,default-trigger="none" | dbootimg /dev/disk/by-partlabel/boot -u dtb 
reboot

c. Note that you can disable it from your host computer as well, just replace /dev/disk/by-partlabel/boot with your boot image and reflash the boot partition with fastboot.

#3

Or a simple way is to have the below line in init script:

echo none | sudo tee /sys/class/leds/apq8016-sbc:yellow:wlan/trigger

It will turn off the Wifi LED trigger during debian boot.

#4

Hi @Mani, I went to the command line (terminal) and did:

sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:yellow:wlan/trigger

But nothing happened. ( I am on Dragonboard 410c with Linaro)

#5

But nothing happened. ( I am on Dragonboard 410c with Linaro)

It is supposed to turn OFF the trigger for Wifi LED. After executing this command, the Wifi LED won’t blink at all.

It is working at my end. What are the directories listed under /sys/class/leds/?

#6

@Nadav_B, are you sure it is the WiFi LED that is blinking? The WiFi lamp is near the middle of the board (and clearly labelled “WIFI”).

However by default there is also a flashing LED between the two USB type A socket (and labelled “1”). This LED flashes with a heart beat pattern (thump, thump, pause) and the BPM increases under load. Whilst the state can be hacked using a shell script it’s probably best to turn off this light from the DTB (as @Loic suggests, but substituting led@1 for led@5) rather than using an init script since I think it is likely to start flashing before the shell script runs.

#7

Sorry for the delay guys,
@Loic, regarding your solution (b),

  1. This solution shouldn’t erase any data, right? So after the reboot everything should work as normal?

  2. You wrote “/dev/disk/by-partlabel/boot”. What should I put in there?
    If I type lsblk, I get:

    NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
    mmcblk0 179:0 0 7.3G 0 disk
    |-mmcblk0p1 179:1 0 2K 0 part
    |-mmcblk0p2 179:2 0 512K 0 part
    |-mmcblk0p3 179:3 0 512K 0 part
    |-mmcblk0p4 179:4 0 1M 0 part
    |-mmcblk0p5 179:5 0 512K 0 part
    |-mmcblk0p6 179:6 0 16K 0 part
    |-mmcblk0p7 179:7 0 1M 0 part
    |-mmcblk0p8 179:8 0 64M 0 part
    |-mmcblk0p9 179:9 0 1M 0 part
    `-mmcblk0p10 179:10 0 7.1G 0 part /
    mmcblk0boot0 179:32 0 4M 1 disk
    mmcblk0boot1 179:64 0 4M 1 disk
    mmcblk0rpmb 179:96 0 4M 0 disk

So what should I put there?

@Mani, I changed the LED id and it worked.
I did now:
sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:green:user1/trigger
and this finally turned off the LED.

@danielt so apparently it is user1 LED. What is the purpose of this LED? Why it blinks when there are no USB devices connected?

Thanks to all of you for the great support!

#8

It will rewrite part of the boot partition. However changing the led triggers is unlikely to cause any problems so, yes, it should work as normal.

Put in /dev/disk/by-partlabel/boot! It is a soft link created automatically during device discovery.

It is a power and load indicator. The LED flashes with a heart beat pattern (thump, thump, pause) and the BPM increases under load.

1 Like
#9

Hi Daniel,

I turn off all the leds (using python):

    os.system("sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:blue:bt/trigger")
    os.system("sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:green:user1/trigger")
    os.system("sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:green:user2/trigger")
    os.system("sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:green:user3/trigger")
    os.system("sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:green:user4/trigger")
    os.system("sudo echo none | sudo tee /sys/class/leds/apq8016-sbc:yellow:wlan/trigger")

But still there are green leds blinking. See photo.

unnamed
unnamed3024×4032 963 KB

Any ideas?

#10

I think I found the solution.

I have to write a slash before the “:”

sudo echo none | sudo tee /sys/class/leds/apq8016-sbc\:blue\:bt/trigger

#11

I think a slash is missing before the colon