Hi,
I’m trying to use the LED4 and LED5 on my apalis imx8qp on a ixora v1.2 carrier board.
I used the imx8qp-apalis-v1.1-ixora-v1.2.dtb device tree.
I can see the leds in sysfs under /sys/class/leds/LED_4_GREEN/brightness and I’m able to set and read the brightness, but the LEDs still stay all on.
Do you have any tips for further investigation?
Best regards, Jonas
Hi @jonas-licht ,
Can you please share which OS you’re using and which version?
Also, can you check if you have some trigger set for the LEDs?
If it’s not none then try setting it to none.
Best Regards
Kevin
Hi @kevin.tx ,
I’m using the Apalis-iMX8_Reference-Minimal-Image-Tezi_5.5.0+build.15 OS.
And the trigger is set to none:
root@apalis-imx8- ~# cat /sys/class/leds/LED_4_GREEN/trigger
[none] kbd-scrolllock kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock mmc0 disk-activity disk-read disk-write ide-disk heartbeat cpu cpu0 cpu1 cpu2 cpu3 cpu4 default-on panic mmc1 rfkill-any rfkill-none bluetooth-power
Best regards,
Jonas
Hi @jonas-licht ,
Looking at the schematic:
The Ixora board does not have a default regulation of the leds. Linux by default populates the sys/class/leds section with the brightness option.
A workaround would be to toggle the pin to generate a PWM signal to adjust the brightness in this way. Not sure what effect this has on the performance though.
Can you maybe further elaborate on what the intention of this is?
Is the goal literally to change the brightness of the LEDs? Or is there a different task behind it?
Best Regards
Kevin
Hi @kevin.tx,
our use case is simple to turn on and off the LED.
Dimming is not needed.
But even if the brightness in the sysfs is set to zero, the LED stays on.
Best regards,
Jonas
Hi @jonas-licht ,
we did some further tests on our side and it seems like there’s something off on our end.
We’re investigating this and I’ll come back to you as soon as possible.
Best Regards
Kevin
