Do I need an extension board for V-by-One video output?
Can I get some details?
The product details page of VIM4 never mentions about it.
At the " Quad Display Interfaces - HDMI, MIPI-DSI, V-by-One & eDP" section, it just says that “the number of independent displays will be limited by the OS”.
And, I asked couple of questions via Khadas homepage web chat, and got those answers.
For your question - Does it support V-by-One video output on linux and android?
→ yes but currently the port is not functional. We will release a special extension baord for it in Q2. Then the VB1 port will be full functional.
for your question - how can I configure V-by-One output framerate and resolution (both linux and android?
→ We will release some documents for it in Q2 I believe.
Then, asked one more question and no answer.
Okay. Thanks. BTW, I see that V-by-One ports already exist on VIM4. Why do I need an extension board for V-by-One?
→ ignored
So I am asking to the forum.
Hope to see some responses.
1/The V-by-One port on VIM4 was a 30 pins FPC connector and its pin definition is made by us;
2/There are many VBO screens on the market,something like 34 inches, 43 inches ,65 inches and so on;Their signal input connectors may or may not be the same;And their logic power input voltage may be different;
So you may need to make an extra board or FPC cable for VIM4 to connect the screens!
Thanks, @Totti
I asked a H/W expert about it and he said that he can deal with H/W things, like bridge board, pin maps, and FPC.
And also he mentioned that V-by-One is kind of market de-facto standard for display panels, so he didn’t have any issues with display panels and boards on his previous projects.
But, based on the response from Khadas, it seems like the V-by-One of VIM4 is not functional yet.
I wish you guys release S/W and documents soon!
Thanks, @goenjoy
You convinced me. I’ve ordered couple of VIM4 to try out for my project
Hope I can check the basic funtionalities before the official release of the source codes and the documents.
Thanks again, @goenjoy !
I believe that you mentioned it here because V-by-One works on that firmware.
You guys are working hard, I know, and one last thing I’m waiting for is the documentaion about v-by-one configuration including resolution change, HDR setting, refresh rate, and so on.
Sorry, there is no relevant document about VBO at present. But I can tell you about the VBO dts configuration here:
bootloader/uboot/board/khadas/configs/kvim4.h
The board VBO electrical connection is selected as follows: lcd1->vbyone_1
The yellow box indicates that you can configure VBO related parameters.
The default resolution of the code is 3840*2160.
Thanks for your reply, I will try to clarify my questions. Due to forum limitations I have to split up my answer in multiple posts (as I am not allowed to have multiple links and image references as a new user).
Q2: image bit depth?
Clarification: Can I assume that lcd_bits = 10 together with byte_mode = 4 and color_fmt = 4 refers to the 30bpp RGB /YCbCr444 color mapping in “VBO HS standard 1.52, chapter 4.1 Byte length and Color Mapping”
(forum rules prevents me from adding more images of the dts settings)
Q4: pixel data order on the 8x VBO lanes?
Clarification: See “VBO HS standard 1.52, chapter 4.2 Multiple Data Lane Combination”. Is region_num = 1, specifying that pixels are transferred like Figure 27? (and not like Figure 28,29?)
(forum rules prevents me from adding image of the dts setting)
