Arduino uno with multiple oled displays

Hello forum!

So I'm working on an arduino project to display data on 2 different oled displays, I'm using an arduino uno with a cd4051 multiplexer and 2 sh1106 oled displays.
I connected the selector pins of the multiplexer to 3 pins of the arduino and now i want to use the u8g library to display different data on these 2 oled displays.

Any tip to achieve that?

Hi @waokasha_99

welcome to the arduino-forum.
I'm pretty sure that you agree and will follow the way how to solve your problem mimimum 200 minutes faster.
This requires to invest 20 minutes of your precious time to read how to speedup solving your problems.

Directly after registering you got presented informations how to speed up solving your problem.
You should really read it.

You will have to post a lot of more information that others can be of help
read the tutorial to know what kind of details are imprortant

best regards Stefan

I2C device usually offers a way to select or change its I2C address.
Change the address of one of them and you can use them on the same I2C bus.
In case of SSD1306 OLED, it has a selector to switch between two I2C addresses.
image

If your OLEDs are addressable (zero ohm resistors shorting address pads), change one OLEDs address and use both OLEDs on the same SCL/SDA pins.

If your OLEDs are not addressable, use an I2C expander... Arduino talks to expander, expander talks to OLEDs.

I do not think your mux is an I2C expander (mux)

This high angled picture does show it in limited quality


You create a solder-bridge either between the yellow marked solder-pads
which gives adress 0x78

or
between the pink marked solder-pads which give adress 0x7A

best regards Stefan

The oled that im working with doesn't have this option, it's an sh1106 128x64.

In this case how do i initiate 2 displays in the code and display data on both at the same time?

What do you mean by I2C expander? The mux that im working with has an 8 channel output and a com input, so im supplying the sda data to this com input and outputting it from the different outputs by playing on the selector pins.

I need a more efficient way to display on both screens at the same time without changing the selector bits every time i want to display data.

Same as you have, I guess.

An Ardunio Uno has only one I2C-bus.

an i2C-muliplexer switches both SDA and SCL to different "bus-outputs"

The I2C-multiplexer type TCA9548A like metioned above is very simple to drive
The following function shows it

void TCA9548A(uint8_t p_busNr) {
  Wire.beginTransmission(0x70);  // TCA9548A address is 0x70
  Wire.write(1 << p_busNr);          // send byte to select bus
  Wire.endTransmission();
}

If you connect your first I2C-OLED to output-channel 1
you call

TCA9548A(1);

and all following commands will be sent to OLED1

If you connect your first I2C-OLED to output-channel 1
you call

TCA9548A(2);

and all following commands will be sent to OLED2

That's it. It does not get easier than this.
except you use a different microcontroller that has two I2C-interfaces

best regards Stefan

Although we might be able to image what you have done, the description does not do the job. You should provide a schematic (photo of paper/pencil drawing is fine).

A CD4051 is not an I2C multiplexer; use what is recommended in the by the others.

I did exactly this and nothing displayed on the screens, wonder why.

i connected the scl and sda pins of the mux to the scl and sda of the esp32 board, then connected the sc0/sd0, sc1/sd1 to the screens and ofc all the other power supplies but still nothing happened.

Did i do anything wrong?

How should I know from such a short text-description?
You will have to post

  • the complete sketch
  • a picture of your microcontroller, I2C-multiplexer and your displays where all the wiring can be seen

best regards Stefan

Okay so:

  1. Connections of screens:
    • vcc -> board 3.3V
    • gnd -> board gnd
    • scl -> sc0, sc1 respectively on multiplexer
    • sda -> sd0, sd1 respectively on multiplexer
  2. Connections of board:
    • scl (pin 22) -> scl on multiplexer
    • sda (pin21) -> sda on multiplexer
  3. connections of multiplexer:
    • stated above
  4. code:
void tcaselect(uint8_t i2c_bus) {
    Wire.beginTransmission(MUX_Address);
    Wire.write(1 << i2c_bus);
    Wire.endTransmission(); 
}

// Initialize the displays 
void DisplayInit(){

    for (int i = 0; i < 2; i++) {
      tcaselect(i);   // Loop through each connected displays on the I2C buses  
  		u8g2.firstPage();
  		do {
  			u8g2.begin();  // Initialize display
  		 } while( u8g2.nextPage() );
    }
}

i realized the code is getting stuck in the do while loop, no idea why.

pictures:



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

Several people wrote you that we need a full code.
If you continue to send snippets, you can hardly expect help

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.

The firstpage/nextpage loop is not used for begin()

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

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

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

1 Like

Here is a Demo-Code found in the U8G2-example-subfolder modified to work with the I2C-multiplexer.

Though I am not sure if it will work this way with calling
u8g2.begin();
two times

/*
  HelloWorld.ino

  Universal 8bit Graphics Library (https://github.com/olikraus/u8g2/)

  Copyright (c) 2016, olikraus@gmail.com
  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification, 
  are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice, this list 
    of conditions and the following disclaimer.
    
  * Redistributions in binary form must reproduce the above copyright notice, this 
    list of conditions and the following disclaimer in the documentation and/or other 
    materials provided with the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  

*/

#include <Arduino.h>
#include <U8g2lib.h>

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

/*
  U8g2lib Example Overview:
    Frame Buffer Examples: clearBuffer/sendBuffer. Fast, but may not work with all Arduino boards because of RAM consumption
    Page Buffer Examples: firstPage/nextPage. Less RAM usage, should work with all Arduino boards.
    U8x8 Text Only Example: No RAM usage, direct communication with display controller. No graphics, 8x8 Text only.    
*/

// Please UNCOMMENT one of the contructor lines below
// U8g2 Contructor List (Frame Buffer)
// The complete list is available here: https://github.com/olikraus/u8g2/wiki/u8g2setupcpp
// Please update the pin numbers according to your setup. Use U8X8_PIN_NONE if the reset pin is not connected
//U8G2_NULL u8g2(U8G2_R0);  // null device, a 8x8 pixel display which does nothing
//U8G2_SSD1306_128X64_NONAME_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 12, /* dc=*/ 4, /* reset=*/ 6); // Arduboy (Production, Kickstarter Edition)
//U8G2_SSD1306_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_3W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_3W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
//U8G2_SSD1306_128X64_ALT0_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // same as the NONAME variant, but may solve the "every 2nd line skipped" problem
//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* reset=*/ 8);
U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);   // All Boards without Reset of the Display
//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 16, /* data=*/ 17, /* reset=*/ U8X8_PIN_NONE);   // ESP32 Thing, pure SW emulated I2C
//U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /* clock=*/ 16, /* data=*/ 17);   // ESP32 Thing, HW I2C with pin remapping
//U8G2_SSD1306_128X64_NONAME_F_6800 u8g2(U8G2_R0, 13, 11, 2, 3, 4, 5, 6, A4, /*enable=*/ 7, /*cs=*/ 10, /*dc=*/ 9, /*reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_8080 u8g2(U8G2_R0, 13, 11, 2, 3, 4, 5, 6, A4, /*enable=*/ 7, /*cs=*/ 10, /*dc=*/ 9, /*reset=*/ 8);
//U8G2_SSD1306_128X64_VCOMH0_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // same as the NONAME variant, but maximizes setContrast() range
//U8G2_SSD1306_128X64_ALT0_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // same as the NONAME variant, but may solve the "every 2nd line skipped" problem
//U8G2_SSD1306_102X64_EA_OLEDS102_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // same as the NONAME variant, but may solve the "every 2nd line skipped" problem
//U8G2_SSD1312_128X64_NONAME_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1312_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ 8);
//U8G2_SSD1312_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8);
//U8G2_SH1106_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
//U8G2_SH1106_128X64_VCOMH0_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);    // same as the NONAME variant, but maximizes setContrast() range
//U8G2_SH1106_128X64_WINSTAR_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // same as the NONAME variant, but uses updated SH1106 init sequence
//U8G2_SH1106_128X32_VISIONOX_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); 
//U8G2_SH1106_128X32_VISIONOX_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1106_72X40_WISE_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1107_64X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1107_128X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1107_128X128_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8);
//U8G2_SH1107_128X80_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8);
//U8G2_SH1107_PIMORONI_128X128_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8);
//U8G2_SH1107_SEEED_128X128_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);
//U8G2_SH1107_SEEED_128X128_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
//U8G2_SH1107_SEEED_96X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1107_HJR_OEL1M0201_96X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1107_TK078F288_80X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1108_160X160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1122_256X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);       // Enable U8G2_16BIT in u8g2.h
//U8G2_SH1122_256X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);        // Enable U8G2_16BIT in u8g2.h
//U8G2_SSD1306_128X32_UNIVISION_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 21, /* data=*/ 20, /* reset=*/ U8X8_PIN_NONE);   // Adafruit Feather M0 Basic Proto + FeatherWing OLED
//U8G2_SSD1306_128X32_UNIVISION_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);   // Adafruit Feather ESP8266/32u4 Boards + FeatherWing OLED
//U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);  // Adafruit ESP8266/32u4/ARM Boards + FeatherWing OLED
//U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /* clock=*/ SCL, /* data=*/ SDA);   // pin remapping with ESP8266 HW I2C
//U8G2_SSD1306_128X32_WINSTAR_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /* clock=*/ SCL, /* data=*/ SDA);   // pin remapping with ESP8266 HW I2C
//U8G2_SSD1306_64X48_ER_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // EastRising 0.66" OLED breakout board, Uno: A4=SDA, A5=SCL, 5V powered
//U8G2_SSD1306_48X64_WINSTAR_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   
//U8G2_SSD1306_64X32_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); 
//U8G2_SSD1306_64X32_1F_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); 
//U8G2_SSD1306_96X16_ER_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // EastRising 0.69" OLED
//U8G2_SSD1306_72X40_ER_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // EastRising 0.42" OLED
//U8G2_SSD1306_96X40_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // EastRising 0.42" OLED
//U8G2_SSD1320_160X132_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1320_160X132_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   
//U8G2_SSD1320_160X80_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1320_160X80_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1322_NHD_256X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Enable U8G2_16BIT in u8g2.h
//U8G2_SSD1322_NHD_256X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Enable U8G2_16BIT in u8g2.h
//U8G2_SSD1322_NHD_128X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1322_NHD_128X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1325_NHD_128X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_SSD1325_NHD_128X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD0323_OS128064_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_SSD0323_OS128064_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1326_ER_256X32_1_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);         // experimental driver for ER-OLED018-1
//U8G2_SSD1327_SEEED_96X96_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);  // Seeedstudio Grove OLED 96x96
//U8G2_SSD1327_SEEED_96X96_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); // Seeedstudio Grove OLED 96x96
//U8G2_SSD1327_EA_W128128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_EA_W128128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_EA_W128128_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 5, /* data=*/ 4, /* reset=*/ U8X8_PIN_NONE);
//U8G2_SSD1327_EA_W128128_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);  /* Uno: A4=SDA, A5=SCL, add "u8g2.setBusClock(400000);" into setup() for speedup if possible */
//U8G2_SSD1327_MIDAS_128X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_MIDAS_128X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_MIDAS_128X128_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); /* Uno: A4=SDA, A5=SCL, add "u8g2.setBusClock(400000);" into setup() for speedup if possible */
//U8G2_SSD1327_WS_128X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_WS_128X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_VISIONOX_128X96_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1327_VISIONOX_128X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1329_128X96_NONAME_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1329_128X96_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1329_96X96_NONAME_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1329_96X96_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1329_96X96_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ A4, /* dc=*/ A2, /* reset=*/ U8X8_PIN_NONE); //  Adafruit Feather 32u4 Basic Proto
//U8G2_SSD1305_128X32_NONAME_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X32_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X32_ADAFRUIT_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X32_ADAFRUIT_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X64_ADAFRUIT_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X64_ADAFRUIT_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X64_RAYSTAR_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1305_128X64_RAYSTAR_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1309_128X64_NONAME0_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1309_128X64_NONAME0_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1309_128X64_NONAME2_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1309_128X64_NONAME2_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1316_128X32_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1316_128X32_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1316_96X32_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1316_96X32_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   
//U8G2_SSD1317_96X96_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // not tested, not confirmed
//U8G2_SSD1317_96X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // not tested, not confirmed
//U8G2_SSD1318_128X96_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_SSD1318_128X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_LD7032_60X32_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* cs=*/ 9, /* dc=*/ 10, /* reset=*/ 8); // SW SPI Nano Board
//U8G2_LD7032_60X32_F_4W_SW_I2C u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* reset=*/ U8X8_PIN_NONE);  // NOT TESTED!
//U8G2_LD7032_60X32_ALT_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* cs=*/ 9, /* dc=*/ 10, /* reset=*/ 8); // SW SPI Nano Board
//U8G2_LD7032_60X32_ALT_F_4W_SW_I2C u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* reset=*/ U8X8_PIN_NONE);  // NOT TESTED!
//U8G2_UC1701_EA_DOGS102_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_UC1701_EA_DOGS102_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_PCD8544_84X48_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Nokia 5110 Display
//U8G2_PCD8544_84X48_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);     // Nokia 5110 Display
//U8G2_PCF8812_96X65_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Could be also PCF8814
//U8G2_PCF8812_96X65_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);           // Could be also PCF8814
//U8G2_HX1230_96X68_F_3W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* reset=*/ 8);
//U8G2_HX1230_96X68_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_KS0108_128X64_F u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*dc=*/ 17, /*cs0=*/ 14, /*cs1=*/ 15, /*cs2=*/ U8X8_PIN_NONE, /* reset=*/  U8X8_PIN_NONE);   // Set R/W to low!
//U8G2_KS0108_ERM19264_F u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*dc=*/ 17, /*cs0=*/ 14, /*cs1=*/ 15, /*cs2=*/ 16, /* reset=*/  U8X8_PIN_NONE);  // Set R/W to low!
//U8G2_HD44102_100X64_F u8g2(U8G2_R0, 4, 5, 6, 7, 8, 9, 10, 11, /*enable=*/ 2, /*dc=*/ 3, /*cs0=*/ A0, /*cs1=*/ A1, /*cs2=*/ A2, /* reset=*/  U8X8_PIN_NONE);   // Set R/W to low!
//U8G2_T7932_150X32_F u8g2(U8G2_R0, 4, 5, 6, 7, 8, 9, 10, 11, /*enable=*/ 2, /*dc=*/ 3, /*cs0=*/ A0, /*cs1=*/ A1, /*cs2=*/ A2, /* reset=*/  U8X8_PIN_NONE);   // Set R/W to low!
//U8G2_ST7920_256X32_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ U8X8_PIN_NONE, /*dc=*/ 17, /*reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_256X32_F_SW_SPI u8g2(U8G2_R0, /* clock=*/ 18 /* A4 */ , /* data=*/ 16 /* A2 */, /* CS=*/ 17 /* A3 */, /* reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_192X32_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ U8X8_PIN_NONE, /*dc=*/ 17, /*reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_192X32_F_SW_SPI u8g2(U8G2_R0, /* clock=*/ 18 /* A4 */ , /* data=*/ 16 /* A2 */, /* CS=*/ 17 /* A3 */, /* reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_160X32_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ U8X8_PIN_NONE, /*dc=*/ 17, /*reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_160X32_F_SW_SPI u8g2(U8G2_R0, /* clock=*/ 18 /* A4 */ , /* data=*/ 16 /* A2 */, /* CS=*/ 17 /* A3 */, /* reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_128X64_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18 /* A4 */, /*cs=*/ U8X8_PIN_NONE, /*dc/rs=*/ 17 /* A3 */, /*reset=*/ 15 /* A1 */);  // Remember to set R/W to 0 
//U8G2_ST7920_128X64_F_SW_SPI u8g2(U8G2_R0, /* clock=*/ 18 /* A4 */ , /* data=*/ 16 /* A2 */, /* CS=*/ 17 /* A3 */, /* reset=*/ U8X8_PIN_NONE);
//U8G2_ST7920_128X64_F_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* CS=*/ 10, /* reset=*/ 8);
//U8G2_ST7920_128X64_F_SW_SPI u8g2(U8G2_R0, /* clock=*/ 14, /* data=*/ 13, /* CS=*/ 15, /* reset=*/ 16); // Feather HUZZAH ESP8266, E=clock=14, RW=data=13, RS=CS
//U8G2_ST7920_128X64_F_HW_SPI u8g2(U8G2_R0, /* CS=*/ 10, /* reset=*/ 8);
//U8G2_ST7920_128X64_F_HW_SPI u8g2(U8G2_R0, /* CS=*/ 15, /* reset=*/ 16); // Feather HUZZAH ESP8266, E=clock=14, RW=data=13, RS=CS
//U8G2_ST7528_ERC16064_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7528_ERC16064_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_EA_DOGM128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_EA_DOGM128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_64128N_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_64128N_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_EA_DOGM132_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ U8X8_PIN_NONE);  // DOGM132 Shield
//U8G2_ST7565_EA_DOGM132_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ U8X8_PIN_NONE); // DOGM132 Shield
//U8G2_ST7565_ZOLEN_128X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_ZOLEN_128X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_LM6059_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);    // Adafruit ST7565 GLCD
//U8G2_ST7565_LM6059_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Adafruit ST7565 GLCD
//U8G2_ST7565_KS0713_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);    // KS0713 controller
//U8G2_ST7565_KS0713_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);     // KS0713 controller
//U8G2_ST7565_LX12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_LX12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_ERC12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_ERC12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_ERC12864_ALT_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // contrast improved version for ERC12864
//U8G2_ST7565_ERC12864_ALT_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // contrast improved version for ERC12864
//U8G2_ST7565_NHD_C12832_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_NHD_C12832_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_NHD_C12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_NHD_C12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_JLX12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7565_JLX12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7567_PI_132X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  // Pax Instruments Shield, LCD_BL=6
//U8G2_ST7567_PI_132X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  // Pax Instruments Shield, LCD_BL=6
//U8G2_ST7567_JLX12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7567_JLX12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7567_122X32_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7567_122X32_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7567_OS12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7567_OS12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 7, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7567_ENH_DG128064_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_ST7567_ENH_DG128064_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_ST7567_ENH_DG128064I_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_ST7567_ENH_DG128064I_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_ST7567_64X32_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); 
//U8G2_ST7567_HEM6432_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); 
//U8G2_ST7567_ERC13232_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_ST7567_ERC13232_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_ST7571_128X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7571_128X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7571_128X96_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7571_128X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7586S_JLX384160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7586S_ERC240160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST7586S_YMC240160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75160_JM16096_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75160_JM16096_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX172104_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX172104_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX19296_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX19296_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX256128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_WO256X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_WO256X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 9, /* data=*/ 8, /* cs=*/ 7, /* dc=*/ 6, /* reset=*/ 5);  // MKR Zero, Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 7, /* dc=*/ 6, /* reset=*/ 5);  // MKR Zero, Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256160_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256160M_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256160M_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);    // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256160_ALT_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX256160_ALT_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Enable U8g2 16 bit mode for this display
//U8G2_ST75256_JLX240160_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX240160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_ST75256_JLX25664_F_2ND_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8);  // Due, 2nd I2C, enable U8g2 16 bit mode for this display
//U8G2_ST75320_JLX320240_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Enable U8g2 16 bit mode for this display
//U8G2_ST75320_JLX320240_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Enable U8g2 16 bit mode for this display
//U8G2_NT7534_TG12864R_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_NT7534_TG12864R_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_ST7588_JLX12864_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ 5);  
//U8G2_ST7588_JLX12864_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 5);
//U8G2_IST3020_ERC19264_F_6800 u8g2(U8G2_R0, 44, 43, 42, 41, 40, 39, 38, 37,  /*enable=*/ 28, /*cs=*/ 32, /*dc=*/ 30, /*reset=*/ 31); // Connect WR pin with GND
//U8G2_IST3020_ERC19264_F_8080 u8g2(U8G2_R0, 44, 43, 42, 41, 40, 39, 38, 37,  /*enable=*/ 29, /*cs=*/ 32, /*dc=*/ 30, /*reset=*/ 31); // Connect RD pin with 3.3V
//U8G2_IST3020_ERC19264_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_IST3088_320X240_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_IST3088_320X240_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_IST7920_128X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Round display
//U8G2_IST7920_128X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // Round display
//U8G2_LC7981_160X80_F_6800 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RW with GND
//U8G2_LC7981_160X160_F_6800 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RW with GND
//U8G2_LC7981_240X128_F_6800 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RW with GND
//U8G2_LC7981_240X64_F_6800 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RW with GND
//U8G2_LC7981_128X128_F_6800 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 18, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RW with GND
//U8G2_SED1520_122X32_F u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*dc=*/ A0, /*e1=*/ A3, /*e2=*/ A2, /* reset=*/  A4);   // Set R/W to low!
//U8G2_T6963_240X128_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable/wr=*/ 17, /*cs/ce=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RD with +5V, FS0 and FS1 with GND
//U8G2_T6963_256X64_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable/wr=*/ 17, /*cs/ce=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RD with +5V, FS0 and FS1 with GND
//U8G2_T6963_160X80_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable/wr=*/ 17, /*cs/ce=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RD with +5V, FS0 and FS1 with GND
//U8G2_T6963_128X64_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable/wr=*/ 17, /*cs/ce=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RD with +5V, FS0 and FS1 with GND
//U8G2_T6963_128X64_ALT_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable/wr=*/ 17, /*cs/ce=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RD with +5V, FS0 and FS1 with GND
//U8G2_SED1330_240X128_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 17, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect RD with +5V, FG with GND
//U8G2_SED1330_240X128_F_6800 u8g2(U8G2_R0, 13, 11, 2, 3, 4, 5, 6, A4, /*enable=*/ 7, /*cs=*/ 10, /*dc=*/ 9, /*reset=*/ 8); // A0 is dc pin!
//U8G2_RA8835_NHD_240X128_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7, /*enable=*/ 17, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // Connect /RD = E with +5V, enable is /WR = RW, FG with GND, 14=Uno Pin A0
//U8G2_RA8835_NHD_240X128_F_6800 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7,  /*enable=*/ 17, /*cs=*/ 14, /*dc=*/ 15, /*reset=*/ 16); // A0 is dc pin, /WR = RW = GND, enable is /RD = E
//U8G2_UC1601_128X32_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_UC1601_128X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_UC1604_JLX19264_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_UC1604_JLX19264_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_UC1609_SLG19264_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_UC1609_SLG19264_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  
//U8G2_UC1608_ERC24064_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // SW SPI, Due ERC24064-1 Test Setup
//U8G2_UC1608_DEM240064_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // SW SPI, Due ERC24064-1 Test Setup
//U8G2_UC1608_ERC240120_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_UC1608_240X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // SW SPI, Due ERC24064-1 Test Setup
//U8G2_UC1610_EA_DOGXL160_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/  U8X8_PIN_NONE);
//U8G2_UC1610_EA_DOGXL160_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/  U8X8_PIN_NONE);
//U8G2_UC1611_EA_DOGM240_F_2ND_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8); // Due, 2nd I2C, DOGM240 Test Board
//U8G2_UC1611_EA_DOGM240_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Due, SW SPI, DOGXL240 Test Board
//U8G2_UC1611_EA_DOGXL240_F_2ND_HW_I2C u8g2(U8G2_R0, /* reset=*/ 8);  // Due, 2nd I2C, DOGXL240 Test Board
//U8G2_UC1611_EA_DOGXL240_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // Due, SW SPI, DOGXL240 Test Board
//U8G2_UC1611_EW50850_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7,  /*enable=*/ 18, /*cs=*/ 3, /*dc=*/ 16, /*reset=*/ 17); // 240x160, Connect RD/WR1 pin with 3.3V, CS is aktive high
//U8G2_UC1611_CG160160_F_8080 u8g2(U8G2_R0, 8, 9, 10, 11, 4, 5, 6, 7,  /*enable=*/ 18, /*cs=*/ 3, /*dc=*/ 16, /*reset=*/ 17); // Connect WR1 and CD1 pin with 3.3V, connect CS0 with cs, WR0 with enable, CD with dc
//U8G2_UC1611_IDS4073_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Enable U8g2 16Bit Mode 
//U8G2_UC1611_IDS4073_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);    // Enable U8g2 16Bit Mode 
//U8G2_UC1617_JLX128128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_UC1617_JLX128128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_UC1638_192X96_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_UC1638_192X96_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_UC1638_192X96_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* reset=*/ 8);  // u8g2 test board: I2C clock/data is same as SPI, , I2C default address is 0x78
//U8G2_SSD1606_172X72_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);   // eInk/ePaper Display
//U8G2_SSD1607_200X200_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // eInk/ePaper Display, original LUT from embedded artists
//U8G2_SSD1607_GD_200X200_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Good Display
//U8G2_SSD1607_WS_200X200_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Waveshare
//U8G2_IL3820_296X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // WaveShare 2.9 inch eInk/ePaper Display, enable 16 bit mode for this display!
//U8G2_IL3820_V2_296X128_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);  // ePaper Display, lesser flickering and faster speed, enable 16 bit mode for this display!
//U8G2_MAX7219_64X8_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ U8X8_PIN_NONE);
//U8G2_MAX7219_32X8_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ U8X8_PIN_NONE);
//U8G2_MAX7219_8X8_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 11, /* data=*/ 12, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ U8X8_PIN_NONE);
//U8G2_LS013B7DH03_128X128_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ 8); // there is no DC line for this display
//U8G2_LS027B7DH01_400X240_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ 8); // there is no DC line for this display, SPI Mode 2
//U8G2_LS027B7DH01_M0_400X240_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ 8);  // there is no DC line for this display, SPI Mode 0
//U8G2_LS013B7DH05_144X168_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ U8X8_PIN_NONE, /* reset=*/ 8); // there is no DC line for this display
//U8G2_ST7511_AVD_320X240_F_8080 u8g2(U8G2_R0, 13, 11, 2, 3, 4, 5, 6, A4, /*enable/WR=*/ 7, /*cs=*/ 10, /*dc=*/ 9, /*reset=*/ 8); // Enable U8g2 16Bit Mode and connect RD pin with 3.3V/5V
//U8G2_S1D15721_240X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_S1D15721_240X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_GU800_128X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_GU800_128X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);


// End of constructor list

#define MUX_Address 0x70

void tcaselect(uint8_t i2c_bus) {
    Wire.beginTransmission(MUX_Address);
    Wire.write(1 << i2c_bus);
    Wire.endTransmission(); 
}


void setup(void) {
  tcaselect(0);
  u8g2.begin();

  tcaselect(1);
  u8g2.begin();
}


void loop(void) {
  tcaselect(0);
  u8g2.clearBuffer();         // clear the internal memory
  u8g2.setFont(u8g2_font_ncenB08_tr); // choose a suitable font
  u8g2.drawStr(0,10,"Hello World!");  // write something to the internal memory
  u8g2.sendBuffer();          // transfer internal memory to the display
  delay(1000);  

  tcaselect(1);
  u8g2.clearBuffer();         // clear the internal memory
  u8g2.setFont(u8g2_font_ncenB08_tr); // choose a suitable font
  u8g2.drawStr(0,10,"Hello World!");  // write something to the internal memory
  u8g2.sendBuffer();          // transfer internal memory to the display
  delay(1000);  
}

best regards Stefan

So this is the full code:

#include "Wire.h"
#include <U8g2lib.h>
#define MUX_Address 0x70 // TCA9548A Encoders address

U8G2_SH1106_128X64_NONAME_1_HW_I2C u8g2(U8G2_R0);

// Initialize I2C buses using TCA9548A I2C Multiplexer
void tcaselect(uint8_t i2c_bus) {
    Wire.beginTransmission(MUX_Address);
    Wire.write(1 << i2c_bus);
    Wire.endTransmission(); 
}

// Initialize the displays 
void DisplayInit(){

    for (int i = 0; i < 2; i++) {
      tcaselect(i);   // Loop through each connected displays on the I2C buses  
  		u8g2.firstPage();
  	        u8g2.begin();  // Initialize display
    }
}

void setup(){//{{
    Serial.begin(9600);
    Serial.println("before DisplayInit");
 	  DisplayInit(); // Initialize the displays 
    Serial.println("After DisplayInit");


    for (int i = 0; i < 2; i++) {
    tcaselect(i);

  
    u8g2.firstPage();
    do { 
      u8g2.setFont(u8g2_font_ncenB10_tr);
      u8g2.drawStr(0,15,"Hello World!");
    } while( u8g2.nextPage() );
    delay(50);
  }

Also I tested each screen alone with and without the multiplexer, worked without but with the mux it kept getting stuck in the loop.

I will make sure to solder the wires, and run the I2C-scanner test. But for now any issue with the code?

Yes.

use Ctrl-T to autoformat the code to make visible which code belongs to what block
aka if-conditions etc.