touchscreen not working on latest bookworm duetpi image

[Tinchus]

Hello. Im using a waveshare 7inch (H) hdmi touch screen . Iworked ok with all versions of duet pi . On one of the last updates i had troubles, but after some cnfig I made it work. There was a problem with that image wich I reported and then was solved (by crisham I think?). Now I have downloaded the latest image, the touchscreen is not working (it is just black , seems to never turn on) and the config it worked before now it is just not working so maybe there was something new on the image?
has somebody else had the problem?
Thanks in advance (duet3, sbc mode, latest firmware 3.5.4)

[T3P3Tony]

@Tinchus which Raspberry pi are you using and which Duet Pi image (32 or 64 bit?) I have tested the 64 bit version with a touch screen recently and it working in my case.

[Tinchus]

@T3P3Tony thank for the reply. Im using a raspi 3 b+ and the 32 bits image, the 64 bits version has a really bad impact on the perfomance of this raspberry pi.

[Electriceye]

@Tinchus

I know you mentioned that your display is the Waveshare 7" model connected via HDMI, I had a similar issue with the Duet 7" PanelDue and version. 3.5.4...it simply would not work via HDMI with the Duet Pi 32 bit image. It worked just fine under the Rasp Pi native image. I ended up having to connect it via a10 pin ribbon cable and worked great. So much for HDMI...

I know It's not a solution for you, but just wanted to let you know you were not the only one.
From what I can tell, HDMI trys to use specific display modes, and not automagically, either.

You Tube video covers the basics- Make sure you test the HDMI output outside of Duet Pi first, this proves that your display still works, just not with the current Duet Pi image.
[Fix Black screen on boot | No video output | Raspberry Pi Guide](https://www.youtube.com/watch?v=Sbwedsfov

From what I can tell, the HDMI output is in a display mode that the Duet Pi Image doesn't like...

• Cheers!

[Tinchus]

@Electriceye Thanks for the comments. Problem with your theory is: I have 3 other printer running 3.5.4. Some config, same hardware, some everything but the image version: 2 of them are using 3.5.4 version but have been upgraded to latest everything (firmware and raspbian). The other printer received a frsh new raspi image downloaded like 2 months ago, there were some issues with those images, I report them and there were fiexed. In that printer I had the same issue as know but solution was super easy: just changing a line on config.txt.
This printer now is using an inamge downliaded like 2 or 3 weeks ago, I tried to copy the config, as far as I know it is the same as in the others, but it doesnt work. I know the screen is ok because it works if I connect a usb to the power port.
So definitly it is just something regarding configuration.
Im thinking about just coping the sd card from the other printers and use that, but... im the kind of guy who finds a problem and wants to really solve it but this one is getting difficult lol

[chrishamm]

@Tinchus Did you try this? https://www.waveshare.com/wiki/7inch_HDMI_LCD#Software_Setting

Raspberry Pi OS and DuetPi are nearly identical. If you don't get proper touch events, you may need to switch back to the Wayfire display server using the rpi-config tool (AFAIR that was in the "Advanced" menu).

[Tinchus]

@chrishamm The prpblem is not with the touchscreen, the hole screen just dont turn on.
Regarding https://www.waveshare.com/wiki/7inch_HDMI_LCD#Software_Setting: no, my model is a 7inch hdmi lcd (H), not that model, but I can give a try a guess?

[chrishamm]

@Tinchus So this one? https://www.waveshare.com/wiki/7inch_HDMI_LCD_(H)

[Tinchus]

@chrishamm Yes, that one, without the case (either way both are identical, difference is just the plastic caseing).
Previously the solution on the other printer with the "older" image was the config posted there: dtoverlay=vc4-fkms-v3d
This time that solution is not working.

[chrishamm]

@Tinchus FKMS is no longer supported in the latest Debian Bookworm version, which the latest Raspberry Pi OS version is based on. Full KMS is now enabled by default, I think. I suggest you follow the instructions here and check if you get it working again then: https://www.waveshare.com/wiki/7inch_HDMI_LCD_(H)_(with_case)#Working_with_Raspberry_Pi

[Tinchus]

@chrishamm I have checked and that is the config Im using. In those instructions, i fguess it doesnt matter because they dont talk about bookworm, the ask for changing the overla.
On 1 of the working prointer i have checked OS version and I have this:

No LSB modules are available.
Distributor ID: Raspbian
Description: Raspbian GNU/Linux 12 (bookworm)
Release: 12
Codename: bookworm

So it is using bookworm. On that printer, confg.txt is using this:

Enable DRM VC4 V3D driver

dtoverlay=vc4-fkms-v3d
max_framebuffers=2

So in the printer it is "failing" you ask me to go back to kms? will try (but it was like that at the first boot and wasnt working)
The other setting are checked and in place.

[chrishamm]

@Tinchus Bookworm is the successor of Bullseye, some of the instructions are outdated. But I know of at least one other user who had to insert a custom HDMI mode in config.txt to get the screen fully working. The ones I have here all work out-of-the-box without any custom settings. To be clear, I am talking about this section:

hdmi_force_hotplug=1 
config_hdmi_boost=10
hdmi_group=2 
hdmi_mode=87 
hdmi_cvt 1024 600 60 6 0 0 0

PS: FKMS is NOT supported any more so the overlay for (FKMS) DRM VC4 V3D driver has no effect.

[Tinchus]

@chrishamm yes, that is what I have:

max_usb_current=1
hdmi_force_hotplug=1
config_hdmi_boost=10
hdmi_group=2
hdmi_mode=87
hdmi_cvt 1024 600 60 6 0 0 0
enable_uart=1
dtoverlay=disable-bt

Will continue looking, I have 2 more hs for a print to finish so then I can copy the sdcard from that printer if I can find a solution before that.

[Tinchus]

@chrishamm I solved the problem (so close the topic as solved please). I dont know the causes but this is how it is working now:

.- In config.txt I commented the line

#disable_fw_kms_setup=1

By doing this and rebooting, I can see the raspberry logo at boot but then again all goes white and stays there

So again in config.txt I made the change:
dtoverlay=vc4-kms-v3d to dtoverlay=vc4-fkms-v3d

And these 2 changes solved the problem. Everything in "normal " now, The camera is not working either but it is detected.

On the other printer I checked, and disable_fw_kms_setup=1 is not commented... Documentation says this uses kernel defaults. So my guess is since the difference between both raspi images is the date and I can see a difference on kernel vlaues, there is something internal that makes all this trouble to me.

Either way, it is solved. Thanks for the help