Screen not working (black dots and white lines)

[markthwain1797]

Me again, this is my first breadboard build an I never really used microcontrollers before, so please don't be harsh.

I got this screen in addition to a rasperry pi pico.

My screen looks like the following is no device is connected vs if a bad usb is connected:

I'm not exactly sure I'm on the right path, but my research showed it might be a problem with getting the right driver for "cheap" OLEDs: Link (reddit)

Any help or suggesting is very appreachiated. Thanks in advance.

[cecio]

Hey.

Which firmware version did you uploaded? With this screen you should use the 64 lines version:

USBvalve-0.18.2-64.uf2

or if you are compiling from code, you should change line 86 from

#define OLED_HEIGHT 32

to

#define OLED_HEIGHT 64

Let me know if this helps.

[markthwain1797]

Hi, thank you :)

I actually tested both versions. The pictures above are from the 32 lines version.

If I use the 64 lines version the screen looks like this (without and with bad usb)

[cecio]

Yes, it looks like a compatibility issue with the OLED. Can you try to use one old firmware and in particular https://github.com/cecio/USBvalve/releases/download/v0.17.0/USBvalve-0.17.0-64.uf2

This version was using a different OLED library, give it a try and let me know.

[cecio]

ok, I probably found the reason: your display use the SH1106 chip. The library currently used by USBvalve is the Adafruit SSD1306 and it seems it does not support the other chip:

https://github.com/adafruit/Adafruit_SSD1306/issues/14

Try to use the old firmware as suggested in my previous message, it may work. If not, you probably need to switch the library. I don't know if you are familiar with development or not.

I may consider to switch the library to something with wider support, but I'd like to find something with a solid installed base.

[markthwain1797]

The version you suggested (v0.17.0) seems to work perfectly fine for me. I'd be really interested in testing if you try out different librarys that support types of displays.

[cecio]

OK, great! I'm happy it worked.

I switched to this new library to improve compatibility, but it seems in some cases the old one was better.

I'll try to have a look if I can keep compatibility for both.