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

[adafruit_support_carter]

That STEMMA connector can not be used with the Hyperpixel since it uses GPIO18 which is used by the Hyperpixel for LCD chip select:
https://pinout.xyz/pinout/hyperpixel4

If this modification still does not work, we will not consider it warranty voiding, since we are advising you to try it.

As an alternative to cutting the trace, you can desolder the diode here:

cyberdeck_diode.jpg (507.32 KiB) Viewed 939 times

[takumidesh]

I will attempt to desolder the diode tonight when I get home and will report back if it was succesful.

[Raspi400]

That STEMMA connector can not be used with the Hyperpixel since it uses GPIO18 which is used by the Hyperpixel for LCD chip select:
https://pinout.xyz/pinout/hyperpixel4

If this modification still does not work, we will not consider it warranty voiding, since we are advising you to try it.

As an alternative to cutting the trace, you can desolder the diode here:

cyberdeck_diode.jpg

It's not about if the hyperpixel uses the stemma connector unfortunately, it's about damaging a piece of functionality that I may use in the future.
Do we know if both stemma connectors are going to be disabled by this action or just the one?

[adafruit_support_carter]

It will only affect the one STEMMA connector.

[Avakato]

The other STEMMA, connector #13, is connect to PIN 33 (GPIO 13) (https://pinout.xyz/pinout/hyperpixel4) and that is being used for Green 3 on the HyperPixel 4.0, With the HyperPixel (non-touch) installed, the only available I2C connector is the ones on the back of the display. I am curious on the displays that just work with the Cyberdeck HAT if the diode or maybe even HyperPixel 4.0 is any different.

What is the purpose of the diode, is action as protection for the Pi from 5V signals, as I could not check based on the numbers on the diode, but I think it is is a zener diode? With the diode removed the GPIO is still accessible via the connector through the resistor but care must be taken when using it.

[Raspi400]

Well I did it, it seems to work.... According to the last post though this may be a 5v safety concern for the PI?
Do you have any previous versions of the CyberHat deck I might be able to get vs this one?

[Thundercatsffs]

Can confirm. Carefully cutting that tracer solves the issue. Il be back if it starts misbehaving again ;)

Must say thou, love this company. Forget trying to get any such help from any other large end user comapny <3

[adafruit_support_carter]

This is currently the only version of the Cyberdeck. So for use with the Hyperpixel, the modifications above are the currently suggested fix if you are experiencing the issues described in this thread. This does alter the board. There's a basic pin conflict with that STEMMA connector and the Hyperpixel, so the two can not be used at the same time anyway. If there is a desire to retain the ability to use that STEMMA connector in the future for a non-Hyperpixel connected configuration, then removing the diode would allow that.

[Avakato]

Hmm I am happy and sad that the little fix I found worked for others because that makes wonder if there can be something done in software about it instead. The way I came to that conclusion is that the ribbon cables and direct connection work fine but not with the Cyberdeck Hat so there must be something on it and it only had two connectors. I am happy that a Adafruit does stand behind their product and tries to help people out with it!

Though it is curious that it shows something for a couple seconds then becomes black with backlight only. I am sure there is a way to manually interface with that GPIO and toggle it to see if it can bring it back. Or maybe have a switch or breakable solder pad jumper style?

In the meantime I think Adafruit should put a note on their product page at least warning about possible incompatibility between the two devices. It was the sole reason I got the two together.

[Raspi400]

Hmm I am happy and sad that the little fix I found worked for others because that makes wonder if there can be something done in software about it instead. The way I came to that conclusion is that the ribbon cables and direct connection work fine but not with the Cyberdeck Hat so there must be something on it and it only had two connectors. I am happy that a Adafruit does stand behind their product and tries to help people out with it!

Though it is curious that it shows something for a couple seconds then becomes black with backlight only. I am sure there is a way to manually interface with that GPIO and toggle it to see if it can bring it back. Or maybe have a switch or breakable solder pad jumper style?

In the meantime I think Adafruit should put a note on their product page at least warning about possible incompatibility between the two devices. It was the sole reason I got the two together.

I'm thinking there may be an kernel edit that would help, that's beyond me though. Refer to the post I posted earlier, discussion about firmware update breaking it and producing a flash upon boot as well. I think that was for an octopi scenario, but we are talking about the pi4 architecture... The 400 was slightly different from the dev vid but I'm guessing the GPIO is the same versus the new pcb layout? Anyone know?

[lalcarazmx]

@adafruit_support_carter I can confirm removing the diode you mentioned fixed the screen issue for the touch and non-touch versions.

[Raspi400]

So I guess I was right in that the CyberDeck consumed(with diode/pathway) a little bit of power? Any idea how much?

Otherwise Pi to screen is ok and the pathways with the diode aren't there for safety measures for the GPIO?

Thanks!