DIY 31 Megapixel Enlarger

[keesbran]

Also for posterity here's the display working on my desktop pc which is thankfully still operable. Now I just need to replicate this on the pi!

Nice! I am experimenting with rpi5 now and with the standard config.txt and after adding video=HDMI-A-1:2560x4320@23 in cmdline.txt the screen resolution is recognised! This did not work on the rpi4 though.

HDMI-A-1 "Chimei Innolux Corporation 0x6301 (HDMI-A-1)"
Physical size: 330x180 mm
Enabled: yes
Modes:
640x480 px, 59.939999 Hz
640x480 px, 60.000000 Hz
720x480 px, 59.939999 Hz
720x480 px, 59.939999 Hz
720x480 px, 60.000000 Hz
720x480 px, 60.000000 Hz
2560x4320 px, 23.010000 Hz (current)
Position: 0,0
Transform: normal
Scale: 1.000000

So the 2560x4320 is now recognised as current screen size.
With VNC Viewer I actually can see it. The screen itself is still dark. Now I will add the config elements from the sumaopai config.txt for the hdmi timing. Looking more carefully to this config.txt one sees some copy paste mistakes. Like a double entry for dtparam=i2c_arm=on and two entries for gpu memory: gpu_mem=128 and gpu_mem=192. Both won't harm much I guess.

 

[keesbran]

But when adding the 8k config.txt setting the screen resolution is back to 720x480@60:

HDMI-A-1 "Chimei Innolux Corporation 0x6301 (HDMI-A-1)"
Physical size: 330x180 mm
Enabled: yes
Modes:
640x480 px, 59.939999 Hz
640x480 px, 60.000000 Hz
720x480 px, 59.939999 Hz
720x480 px, 59.939999 Hz
720x480 px, 60.000000 Hz
720x480 px, 60.000000 Hz (current)
2560x4320 px, 23.010000 Hz
Position: 0,0
Transform: normal
Scale: 1.000000

To have the screen recognized op the pi5 I had to add this line from the original config:
# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d

 

[Graham06]

I also tested for the framerate that should be 23Hz. Is that correct?

When I was looking at my settings this evening, I noticed that my framerate was 22Hz

 

[Graham06]

I can't log in using safe mode or even completely wipe the machine and reinstall windows.

I suspect that won't work. I bet the bad info is written to the lcd firware which will persist through a os reinstall.

I think recovery might be possible. I think bitlocker prevents someone reading the drive data when the drive is installed in another computer:

1:
- plug in an external monitor to the hdmi port
- you can use your tv or your now working mono lcd
- switch the login screen to the lcd. this might be via windows-P or F8. can't test myself

2:
- turn on your laptop, and old pc in the same lan
- on the old pc see if you can see the laptop in the "Network" section of "My Computer"
- alternatively log into your router/dhcp provider and find the IP of the laptop
- this to be able to run "ping laptopname" or "ping laptopip" from start->run->cmd on the old pc
- in a cmd window on old pc run "net use x: \\laptopname\c$ /u:userwithadminrights *" (is the final * needed?)
- place a batch file in x:\Users\UserName\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup
- you'll have to log in as Username on the laptop, which might be a bit tricky
- alternatively edit something under x:\window\system32\ I've done this before but can't remember what and the internet seems useless these days. I edited a batch file or temporarily replaced an unimportant .exe with an .exe that did what I wanted.

 

[keesbran]

This is what I know until now. When using the sumaopai config.txt I can see the screen showing some activity on the rpi4 but it blacks out after some time. The screen does not show up when passing the wlr-randr command. When adding:

# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d

to config.txt and a reboot I don't see the screen activity anymore but the screen shows up in with wlr-randr although with the wrong resolution and I found no way to force it to the right one it got from cmdline.txt.

Also with this 'forced' kms an edid file is created at

/sys/class/drm/card1-HDMI-A-1/edid

With:

edid-decode /sys/class/drm/card1-HDMI-A-1/edid

I was able to decode and see it. See attached file for the screen connected to the rpi4. At this level things seem to go wrong. Force kms or not? How to get cmdline.txt settings respected? The edid that seems to reflect that. Conclusion: hardly any progress. I could replicate this also on the rpi5 where the edid was identical. But without the kms line it did not show any screen activity. Maybe kms is loaded by default on the rpi5 though.

Enough for today