Arduino uno with multiple oled displays

[StefanL38]

@waokasha_99

As you see in the picture I'm only printing "hello world" at the moment so there is no full code, just the ones I sent plus the constructor of the screens. But at the moment I want to see what the problem is then go on with the code.

You uploaded a sketch that makes one OLED show "Hello World"
And you should post this complete sketch
that does print the "Hello World"

You are using

u8g2.begin();
u8g2.firstPage();
u8g2.nextPage()

where it is UNclear what is happening inside these function-calls
and how does some eventual preparation look like.

What is so hard about posting this complete Hello-World-sketch??
You can do it using this method with a few mouse-clicks

Make experienced users help: two ways to quickly post code as a code-section

Hi newcomer, This thread wants to show you how you can speed-up getting helpful answers with small effort. If you manage at least to post this way. You have the sympathy of the experienced users. If you are willing to invest another 20 minutes these 20 minutes extra-time will save you a minimum of 200 minutes to finish your project. always post your full sketch. As a code-section from the very first to the very last line A code-section has a small height => keeps your posting "short" but e…

These pins look UN-soldered. You can't expect that UN-soldered pins give reliable contact.

@waokasha_99

Kinda messy i know but was a bit in a hurry,

You should have learned now:
trying to be fast just slows everything down
for fastest problem-solution take time

• do basic tests one by one
• I2C-Scanner test for each display stand alone
• • I2C-Scanner test for one display connected through I2C-multiplexer
• • I2C-Scanner test for both display connected through I2C-multiplexer
• testing with the most basic possible code that does not use loops
  looks like this

tcaselect(0); // select first display 
// do all the details with first display
u8g2.begin();
u8g2.firstPage();
u8g2.nextPage()

tcaselect(1); // select second display
// do all the details with second display
u8g2.begin();
u8g2.firstPage();
u8g2.nextPage()

• to post the full code = the complete sketch from the very first line to the very last line
• posting picture (what you have done)
• • but posting pictures where the wiring what is connected to what can be seen easily

All that happens if you try to be fast is a delay
with asking back for the details you meant to leave out to post quicker

best regards Stefan