Has anyone ever got the 7" LCD to work?

Banana Pi SBCs design BPI-M3(A83T/R18)
1

I’ve had my M3 together with a 7" LCD display (the S070WV20-CT16 with MIPI DSI and parallel RGB interface - using the DSI interface of course) for some time now, but I’ve not ever gotten the LCD to display anything, even though the screen lights up and the touch interface works. All I ever get are vertical stripes on the display. I’ve exchanged the screen for a new one with my supplier but to no avail. And then themselves tried it too (with another M3 board) with the same results. There is a youtube video showing this combination to work, so it should work in theory.

So now I ask whether one of you has any one of you ever managed to get this screen to work? And if so, what did you use for software and/or what hardware hacks did you use?

NoKey.

2

I don’t have 7" LCD display to give you the steps to make it work and you don’t mention which OS you are using.

script.bin is responsible to set the output, it can be HDMI and/or LCD (or tvout). You have to change script.bin to direct output to LCD and not HDMI or vice-versa. There is a tool provided by sunxi-linux or Armbian to edit the section of the script.bin to change the output, called fex2bin and bin2fex.

There is a section on your script.bin (script.fex when decomplied) you have to set:

;---------------------------------------------------------------------------------- ;disp init configuration ; ;disp_mode (0:screen0<screen0,fb0>; 1:screen1<screen1,fb0>) ;screenx_output_type (0:none; 1:lcd; 3:hdmi;) ;screenx_output_mode (used for hdmi output, 0:480i 1:576i 2:480p 3:576p 4:720p50) ; (5:720p60 6:1080i50 7:1080i60 8:1080p24 9:1080p50 10:1080p60) ;fbx format (0:ARGB 1:ABGR 2:RGBA 3:BGRA 5:RGB565 8:RGB888 12:ARGB4444 16:ARGB1555 18:RGBA5551) ;fbx_width,fbx_height (framebuffer horizontal/vertical pixels, fix to output resolution while equal 0) ;lcdx_backlight (lcd init backlight,the range:[0,256],default:197 ;---------------------------------------------------------------------------------- [disp_init] disp_init_enable = 1 disp_mode = 0

screen0_output_type = 1 screen0_output_mode = 5

screen1_output_type = 3 screen1_output_mode = 5

If you already did this you most likely wired it wrong.

Hope it helps.

3

If that wasn’t set or if it was wired incorrectly, the screen would not even light up. It lights up, which I mentioned in my original post. I have a bachelor’s degree in electronic engineering, specialized in embedded (linux) systems. I generally get things to work where others fail. However, as there’s no decent technical information freely available about this screen (and I mean stuf like electrical interfacing and internal registers), I can’t realy debug things to see what goed wrong. And this is just a hobby project of mine.

4

Oh, i am impressed.

Did i mention to you i have a Bachelor’s degree in Mechanical Engineering, a MBA and hold a Bachelor of Science in Computer Sciences?

The Answer is right in front of you, what you are going to do with it i have no idea. I wanted to help. Yeah, i think i deserved that.

5

Does this lack of actual replies (like a simple “yes” or “no”) on this question mean that there is no one who has even tried this?

6

What is your impression if you look through http://forum.banana-pi.org/c/bpi-m3 ?

Given the state of software and support I would assume most unfortunate BPi M3 customers simply threw their boards away since they only get broken software and no support. :slight_smile:

7

I have seen that very suggestion pop up several times, so it is hard for me to tell whether you’re being sarcastic here…

8

This is what the screen looks like when using the LCD version of android on it: I get the same when I use a modified Linux image that enables and uses the screen. And also when I use a self-compiled image with LCD interface enabled.

9

Hi NoKey,

I was able to get the 7" LCD to work by having a piece of tape stick on the CN2 bus. Basically the the CN2 bus on the LCD screen needs to be held down. It worked for me!

Thanks, V

10

Seems both ones my supplier had were broken. Faulty hardware; what are the chances? Received new ones from China (finally) and these work. So on to more hacking from now on.