Pi400, Cyberdeck, and Hyperpixel4 (non-touch) not working.

[takumidesh]

Hello All,

As stated in the title, I have a new pi400, Cyberdeck and hyperpixel4. Using these in conjunction doesn't seem to work. During boot I will occasionally get a flicker of the screen working for about .5 of a second, but otherwise only the backlight turns on.

I have tried to recreate the issue / isolate it with the devices I have on hand. here is what I have tried

Multiple Power supplies, ranging from 0.5 amps, to 2.5 amps. - no success.

I moved the sd card over to my pi3b and inserted both the cyber deck and the screen (no standoffs or header extensions) and the screen works just fine.
as shown here https://photos.app.goo.gl/HKt1UvyTWfg6VHZY7 around the 53 second mark is the behavior demonstration.



I also have tried to connect the screen directly to the pi400 (no cyberdeck) and it behaves just fine, however it is not useable since it is facing the wrong direction.
see here https://photos.app.goo.gl/rqx2AVABbeXiHZXy6

Here is a video showing the behavior of the screen when connected with the cyberdeck to the pi400
https://photos.app.goo.gl/e94AKASnmDWC2has5

I have gone through the proper install script for the screen, I know it works since it works fine with the 3b and without the cyberdeck.
I don't believe there is an issue with the cyberdeck since it works with the screen + 3b

any help is greatly appreciated

[adafruit2]

jsut to verify, the screen + deck + pi 3b combo works? we are trying to reproduce the issue

[takumidesh]

yes, here is a photo of how I had it connected to to the 3b, https://photos.app.goo.gl/HKt1UvyTWfg6VHZY7

obviously this is not an ideal configuration, but I just had it that way for testing.

[Raspi400]

Hey all, not to hijack the thread, but I've got this issue too.
Been arguing with different things, but I too have the cyberdeck, 400, though I'm using a monitor with it.

I've been able to get the screen to stay on a good 5-10 seconds though with the following in config.txt:
dtoverlay=hyperpixel4
gpio=0-25=a2
gpio=19=op,dh
enable_dpi_lcd=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x7f216
dpi_timings=480 0 10 16 59 800 0 15 113 15 0 0 0 60 0 32000000 6

It still refuses to stay on... Though I think it's still connected to the machine, just not lit up, like when power save turns off the screen on Windows and it just won't come back up..
It shows up in the screen config tool, even lost a window to it earlier until I comment out the HP4

Ok if I continue in this thread or do I need to make my own? Adafruit support sent me here when I expressed concern over possible compatibility therefore I may need to return the 2 screens I got.
Thanks very much!

*edit
A further thought I had, since it's not the fastest machine and hardware related things seem to take a bit~
Could the additional gpio assignments take a moment to process? That would explain why it's gone from a flash of the screen (with nothing connected) to a few seconds or so after connecting hdmi, usb mouse, usb powered speakers... Sorry, linux isn't my strong suit...

[adafruit2]

hihi what would be super helpful is if you can ask pimoroni if they hvae any ideas. we'll also take alook but since the schematics aren't published it will take us longer to divine whats up! :/

[takumidesh]

I posted this same question on the pimoroni forums as well. I am struggling to understand what could be causing this since, I believe the cyberdeck is just a straight passthrough board correct? none of the circuitry that is used for the stemma plugs are anything would even be used if nothing is plugged in correct?

It is also very strange that the board seems to only not work with the pi400. but the screen does in fact work with it.

I am able to occasionally get the screen to show up for about .5 second if i open a terminal and run the hyperpixel4-init script, but that is all, and even that is intermittent in its success.

[Raspi400]

I've invited Lynn Raper from Pimoroni to this thread, perhaps we can figure it out.
They suggested the Flat Hat Hacker board vs the CyberDeck, so perhaps we're just looking at a pin switch or such?

I ordered 2 of these screens from Adafruit but am kinda new to this side of IT. Then of course after testing the 2nd screen to see if the first was defective, I noticed the return policy only accepts unopened products.
Will we be able to return the screens if the CyberDeck/HP4 combo doesn't work?
I'm willing to go the distance to make these work as one is for my nephew! :)

[takumidesh]

I did some more testing. If i start with the screen directly connected to the pi400 (no cyberdeck, facing the wrong way) it starts up just fine with the screen working. If i then unplug the screen, and attach it to the cyberdeck, then plug the cyberdeck + screen into the pi400 and run the hyperpixel4 init script, the screen turns on and stays on with the cyberdeck as intended.

This is not a solution though as it would require doing this whole setup plugging and unplugging everything everytime you turn the pi on.

I just let the pi sit idle for about 10 minutes to see if it would turn off. everything was fine until i actually went to use it. I intended to run htop, and as soon as I hit enter the screen shut off (backlight still running)

[Raspi400]

When you plug the screen directly in, could you share a pic? I can't tell which pin is which, need to find my magnifying glass ;)

[takumidesh]

im just plugging the female header of the screen directly to the back of the pi400. you can see it in this video https://photos.app.goo.gl/rqx2AVABbeXiHZXy6

unfortunately the flat hat wont work since it is flat, not angled 45 degrees.

[Raspi400]

Well shoot, all we have to do is lean a mirror behind the unit and invert the screen :D

I guess a question for the Adafruit folks, is there a pin reconfiguration for the CyberDeck that somehow changes from pi3 to pi4?

[adafruit2]

thats the weird thing, theres' no pin change difference between the pi3 and pi4!

[Raspi400]

Is there a mechanism that might detect the Cyberdeck and change something? Apologies I don't know raspbian too well yet.

I would assume the only thing then is a HyperPixel4 configuration adjustment of some sort? Perhaps a voltage/signal change? You mentioned needing their schematic?

I'll reach out again to them if we don't see something here soon.

I did find this https://github.com/TxBillbr/octodash-hyperpixel-fix and was curious how to rollback the Pi400 eeprom... Not confident enough myself that I would be doing it right and don't want to brick it.
I see here https://github.com/raspberrypi/rpi-eepr ... are/stable , pieeprom-2020-09-03.bin
I believe that would be the version the guy is talking about? Last stable pre December 2020?

[Raspi400]

Is this the schematic you're needing btw?
https://pinout.xyz/pinout/hyperpixel4

Trying to wrap my head around this though, since the screen uses all GPIO pins, and this Pi 400 also uses other hardware on the pins via i2C was it?
Does this mean the voltage required to run the CyberDeck+additional overhead on the Pi400 is more vs the CyberDeck + Pi 3/4? Thus resulting in the output halting vs when it's plugged directly into the 400.

That would explain why this board that's suggested doesn't have the extra components on the side that the CyberDeck has?
https://shop.pimoroni.com/products/flat-hat-hacker

Is there a way to check voltages to the lcd and see a die-off vs multimeter or such?

*Edit
I just verified if I plug the screen directly into the unit and remove the CyberDeck, the screen works just fine. Though I did not comment out dtoverlay=vc4-fkms-v3d and my hdmi monitor turned off as the hyperpixel worked just fine.
Attempting some more and I'll report back

Later:
After running 'sudo ln -s /dev/i2c-3 /dev/i2c-1' it stays on longer than it did before, but still blanks out.
HDMI monitor isn't turning on as well. So I guess it's one or the other, but either way is there a way to verify the voltages, and what voltage does the CyberDeck consume off of the GPIO?

[TalleyWhacker]

I had some problems getting this screen to work but I was finally able to do it (for the most part)! When installing the hyperpixel4 software, instead of choosing the correct prompt for the non touch, I selected the prompt for the touch version. I went from maybe 5 seconds of screen time to actually having full use (to a certain extent). The problems i have encountered have been from running beefier programs. For example: steamlink (the screen flips sideways and crashes after a few minutes), Minecraft (i can get probably about 5 minutes before i get black screened). Hopefully you guys can try that little software trick and figure this out! https://photos.app.goo.gl/vF5ffhkEyt17Daze8