Blue Indicator LED different than Beginners Guide

According to the Beginners GuideB and the KBI guidance if the VIM3 is turned off, the blue LED should be on.

This is not the case on my VIM3. Is there a reason why? I found the setting in Android Pie for the white and red LED but not for blue. (Even so the guide says only white is on but both where on after flashing :slight_smile: )

@MikesCo both white and red LEDs are enabled by default, and are controlled by the SoC itself, the blue LED is operated by the MCU,

If you are seeing both red and white LED glows, it because the system has soft reset and booted up into android,

And the white LED glowing it only for linux images, and red only glows if triggered in the /sys/class/led...

Hope that solves your queries :slightly_smiling_face:


Bit the blue light should be on by default if a the device is off correct? Is there a way to enable this without a serial adapter?

That’s if the device is in a standby or sleep state. When powered off with power still connected, all lights should be off

when powered but turned off its supposed to be blue…

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If you are using official assemblies from Khadas, all indications should be in accordance with the beginner’s guide, however, if you are using third-party assemblies, things may be different, third-party assemblies can be programmed to even completely turn off the led-indication.

Both the system on(systemon) and system off(systemoff) Blue LED state can be configured in KBI. Some KBI functions can be configured when running Krescue from SD card. Unfortunately, I did not see LED config options running KBI in Krescue.
There is a function in KBI running from Krescue to reset the MCU to factory mode. I ran the reset function, now the blue LED is on when the VIM 3 is power connected but off.
By the way, I assume KBI functions could be accessed running the shell from Krescue, but I don’t know the way.

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I will try this. Would be great if this would work “out of the box” :slight_smile:

My serial adapter should arrive this week. How do I access the KBI. Description does only describe how to plug in and than the terminal command. But how do I manage to make the terminal connect to the VIM3? And what’s the code for the reset without using Krescue?

Or do I have to use Krescue for the reset of the MCU? What code did you use to reset?

Here is a video, it shows the VIM3 booting Krescue from an SD card. Next I select MCU reset and follow prompts. Very easy to do.

However, using KBI and a serial tool, you will gain much more control. It is also very easy to use, I foresee no problem with you using the serial tool and KBI.
When your serial tool arrives, we can help you. It is not difficult. Basically it involves connecting the serial tool between PC(USB) and three lines on the serial tool to the VIM3’s GPIO(RX, TX, GND), using a program like Putty for Windows to communicate with the serial tool.

As seen in video, using Krescue. I assume it is possible to do it in other ways, for instance with the VIM3 running Ubuntu, but I don’t know the commands.
You will find having a serial tool a useful diagnostic aid. If at some point Khadas Team techs ask for a boot log, you will be able to provide it using the serial tool.

Thanks for for your fast support! I got Putty. Let me guess, I choose the “serial” option and than click on open? :slight_smile: I Should have seen this earlier…

You will need to confirm the COM port shown in Putty is the same as your serial adapter, you can check Window’s Device Manager under Ports for that. Baud rate needs to be set to 115200, then you will name it and click save. Once the tool is connected, select the name and click load. Boot the VIM3 and let it boot for a log. Or once the VIM3 starts booting, press the space bar on the PC to interrupt the boot. In Putty’s output, you will see a prompt, there you will enter KBI and press enter. From there all KBI functions will be accessible.
I just covered this on the Edge, will be very similar on the VIM3(Baud rates are different for Edges). Have a look at this post.

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Ok will try the second method. “Boot for a log” I don’t understand. (It’s hard beeing a new)
Found the MCU Register Guide. Therefore I guess factory reset is


Boot for a log not needed, just mentioned it in case you ever needed the log.
I forgot about that guide. I think you are correct, but I have not confirmed it myself.

What code did you use? kbi SHUTDOWN_NORMAL 0 did not work

Unfortenatly even so power is connected blue LED is off. KBI shows it should be on.

kedge# kbi led systemoff r
led mode: on [systemoff]
kedge# kbi led systemon r
led mode: off [systemon]

are you using a v13 board revision ?
I am not sure if there has been any changes with that one and KBI, but just want to make sure…

just to make sure the LED is not broken or anything try entering upgrade mode with maskrom mode (triple click F button in 2 seconds of powerup/plugging in power cable)

if the blue LED blinks then, we can be sure the problem isn’t with the LED itself…

I used no code to reset, see video here.