Turn Off/Remove LED on ODROID N2

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whoneyc
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Turn Off/Remove LED on ODROID N2

Unread post by whoneyc » Thu May 16, 2019 3:46 pm

What is the best way to disable the LEDs from blinking on the N2? I'm using my unit for nocturnal video recording, and the LEDs refracted through my acrylic parts shows on video which messes up my computer vision algorithm.
  • Kernel level modification: Previous threads for the HC1 and C2 provide information about echoing none to the blue LED heartbeat. Is this valid for the N2? Can I disable all LED's this way?
  • Soldering: Reading the schematics suggests that the red LED only indicates power and the blue LED is only triggered by the FET connected to the SYS_LED connection. Are these safe to desolder? I ask because I have used LEDs like regular diodes in some of my boards, and I don't want to damage any kind of board protection circuits.
  • Other Methods: Currently, I have some electrical tape covering the LEDs on my N2 in the field. This isn't an elegant or perfect solution, but it does ok. Are there other techniques you use or have used on other projects which achieve the desired result of disabling the LED light?

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odroid
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Re: Turn Off/Remove LED on ODROID N2

Unread post by odroid » Thu May 16, 2019 3:52 pm

You can turn the blue LED off by a GPIO control from software with none option as described in this wiki page.
https://wiki.odroid.com/odroid-n2/appli ... ed_control

But the red one seems to be hard-wired.
Anyway, we will check if there is a way to turn it off or not since the red LED could be off in the suspend mode.
I don't like any ugly desoldering nor taping method either. ;)
But you might need to do it in worst case.

@tobetter,
Do you know how to turn it off in the u-boot suspend mode?
Is it possible to make it off while Kernel is running?
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tobetter
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Re: Turn Off/Remove LED on ODROID N2

Unread post by tobetter » Thu May 16, 2019 4:10 pm

@whoneyc, the BLUE led can be off with the same command.

Code: Select all

echo none > /sys/class/leds/blue\:heartbeat/trigger
Do you want to off the RED led as well?
I've not tried yet, let me check.
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whoneyc (Fri May 17, 2019 1:42 pm)

whoneyc
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Re: Turn Off/Remove LED on ODROID N2

Unread post by whoneyc » Thu May 16, 2019 4:39 pm

tobetter wrote:
Thu May 16, 2019 4:10 pm
want to off the RED led as well?
I've not tried yet, let me check.
It is impossible to turn red off with code. The schematic shows it goes from Vcc to GND directly.

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Re: Turn Off/Remove LED on ODROID N2

Unread post by tobetter » Thu May 16, 2019 4:48 pm

whoneyc wrote:
Thu May 16, 2019 4:39 pm
tobetter wrote:
Thu May 16, 2019 4:10 pm
want to off the RED led as well?
I've not tried yet, let me check.
It is impossible to turn red off with code. The schematic shows it goes from Vcc to GND directly.
Yes,the RED led cannot be off while ODROID-N2 is running.

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Re: Turn Off/Remove LED on ODROID N2

Unread post by odroid » Thu May 16, 2019 5:11 pm

@whoneyc,
Ahhh! You have to cover a small piece of black electrical tape on the red LED. :(
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