Vim3L noob questions

Hello, i am looking for a new board to replace a raspberry pi 3b+, i have a “mini-top” built with it, but honestly it is bad for the purpose, i like psp games and since my psp broke i play the ones i own on it and almost all run, just not very well, i also use it to browse the web, write c# on monodevelop, c++ on vscode and i try to use blender to model 3D prints but i can only get so far, as the polygons go up blender becomes unusable.

So i was looking for boards that fit the case, have the cooling on the top instead of on the bottom to not melt the pla, and are at least a little better and with as little power drain as possible. Comparing the specs the ones i found, vim3L it seems to nail every point, but i have some concerns:

The spec sheet says both khadas vim 3 and 3L support 5-20V, the batteries i am using range from 6,6 to 8.4V, i am using a switching mode DC-DC buck converter to lower it to 5.25V, is it safe to remove it completely and let the board regulate the power as the battery drains?

Also i am taking the audio signal from the 3.5mm jack to feed an amplifier, i really want to use ubuntu because i have been using it for the last 2 years as my main OS and getting rid of debian (well…get a beefier version) will be a blessing, do you think i’m going to run into truble outputing the signal by the GPIO? Was there any isues in doing so in previous vim boards running Ubuntu?

The last question, i was wondering about trying android as well i found a dualboot firmware for the vim 2, will there be a version for vim3L and if not is there any workaround? Thank you.

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I guess the reason why you power the VIM3L with batter module is to delivery a clean and pure power for better sound, right?

Yes, it’s not recommend but for crazy makers you still can power the VIM3/L via USB-C or VIN connector, but note that the VIM3 cannot charge the battery module.

You might need to design a module or board over 40 pin GPIO or M.2, as both I2S interface there.

We provide Ubuntu image official, but for audio and DAP users, we will also develop the Volumio OS for VIM3L in the future.

We don’t have thus to build dual OS for all Khadas SBCs, but instead, we have a more crazy planing, @hyphop may update here when he available.

Have fun!

No, right now i’m using it because i must use a voltage between 4.8 and 5.25v. Allow me to explain diferently.

As you can see in the image the khadas is directly connected to the battery and the voltage of the battery is capable of providing from 6.6v at 0% and 8.4v at 100% charge.
I know the voltage has to be reduced one way or another, the chips are 12nm, a digital high is probably 0,8v, ram uses probably 1v, usb 5v etc… etc…
What i am worried is that for example, the battery is supplying 6.6v khadas sees the 6.6v and says “oh look 6.6v, i am going to lower it to 5v here, 0,8v there etc…” but when i plug the charger the voltage reaching to the board will go from 6.6v to 8.4v instantaneously and all the chips fry. So…are those voltage changes when the board is powered ok or dangerous? Can i just connect the battery to usb C and then to the vim3l port?

Thanks, i will look into it, if i don’t manage to make it i’ll just use a usb to 3.5mm adapter.

Great thank you.

Hello, The VIM3L does not offer analog audio output. SPDIF is available on the GPIO.

Also, I do not know the current(Amps) required by the audio amplifier shown in your “After” diagram, but I believe the 5 volts on the GPIO(Pin 1(5V), Pin 21 (GND)) is limited to 500mAh.

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But i know there is a at least a pwm pin, can i not simulate a analog output via that pin? Even if i ditch the stereo and use only mono and connect the pin to both audio channels on the amplifier?

The amplifier is class D PAM8403 and the output is rated to 3W * 2, but after i turn the potentiometer knob past half the speakers start crackling, anyway i ordered a TDA2822M, should arrive before the board, that one should not cause any problems and be powered via the GPIO.

But i still don’t know, is it safe to use variable voltage input via the usb c on the board? I really need reassuring, i really don’t want to end up frying the board.

Nope, actually, the input voltage range from 5V to 20V will DC-DC to VSYS_3V3 at fixed value of 3.3V, you can check the power tree for the details:

Have fun!


Amazing! Thank you. Getting rid of the external converter should give me more space and extra battery time :smile:

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Tell me where to find at least one firmware on VIM3L with working voice search? With a working awakening through a remote control? None of the firmware on the android works fine :(… bugs and microfreezes are tired of it already (I tried to install a media VLС player from the official app, it doesn’t play the video at all :(… does everyone like everything? Or doesn’t anyone use Vim3L as TV box?

as far as I know, the native Khadas remote does not have such a “voice” mode, but on the Internet you can find instructions for third-party remote controls, many do it, including me :slightly_smiling_face:

what prevents you from trying other players?

but still I recommended you CoreElec, which you didn’t like so much, I have it on vim2 pro and really liked it!

You are “Bubble - tehnozone” (I subscribed to your YouTube channel and therefore chose Khadas)? I remember, you recommended installing chrome and setting up voice control through a browser. I just don’t understand why I need to look for tricks if the developer has to fix such bugs. The developer very poorly supports the Vim3L model, I am not very happy with this (I should not have taken it, since I am essentially a beta tester for my own money :)).

mxplayer (use it).

no thanks, i already used СoreЕleс (with additions, this system starts to slow down, microfreezes are already tired … it is very slowly performing tasks. My android box is 5 years old and it works faster :)).

no, I’m not that Vladimir, I’m different :grin:

don’t worry, maybe you wanted to buy vim3 pro (4/32)? Now it’s just on vim3, CoreElec (nightly build), which is probably why there are problems. At the moment you have the newest processor from Khadas, and it takes time to debug!

Did you try superceleron’s ROMs?
Pie Normal.
Pie ATV.

yes, they already know…

First of all which mic are you using? Android is built on top of linux and linux tipically works very well with usb peripherals so i would give it a one of those a try, second, if it is work without defects (try recording your voice and replaying to yourself), you can always try to launch bash comands with an opensource voice library like julius, or scripts with actiona.

I’m currently using Android TV (superceleron’s logo is indicated at boot :). The image is listed as
VIM3L.Android.TV_FINAL-v1.0-20191023.SC.emmc.kresq, set through the Krescue installer. Without the installer from Krescue, I could not install any other image on Vim3L :frowning: ).

I have 3 remote controls with a built-in microphone :slight_smile: and not one works with VIM3L. By the way, the problem is not only mine. Here in this review (it is in Russian) it is indicated that VIM3L is droped (video 4k 60 fps in youtube does not reproduce) and the microphone does not work either (firmware is not like my Android TV, but - android).

I also had questions at first, but I realized the guys are doing what they can, plus new processors, etc. , so I left this idea to ask for some things that, in my opinion, have a place to be for a " tv-box ", as a result, I have to decide some moments on my own :upside_down_face:

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I’m not sure how far into Development images you used ?
I use the Vim3 and Vim3L via SD Card and SC ATV roms Internal.
Both work Extremely well with both OS’s.

Nightlies 18th February CE is extremely usable for both Vims.
We reverted some commits on 13th Feb Nightly which fixed H264 Decoder
Not sure if you report issues on CE forum ?
It’s imperative to report issues on your Vim3L using Nightlies or your issues may not be solved when a stable release is done for the Vim3L.
PS Not sure what you mean by additions ?

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about one month (maybe more).

What version of ATV are you using (v1 or v2)?

I asked about the problem of SuperCleron, he said that everything works fine :), and for me or another guy in the video, the link (that is, the case is not unique) does not work. And I hope to solve this problem by updating ATV to version # 2, but I can’t do it yet (ATV rom # 1 blocks the boot image from SD card).

filmix, torrent service…

It would certainly be more interesting to see 3/32;4/32, since 2/16 seems to me not enough, otherwise I like vim3L in terms of characteristics! :stuck_out_tongue:
Maybe someday there will be vim3L pro :wink: