Ok, many thanks.
I did DuckDuckGo Serach: SSD1306, it's right the same?
Best regards.

@György-Farkas said in GPIO connections may affect Omega operation:

@Paolo-carrer The OLED Expansion is hardware compatible with the original Omega and Omega2.
The Q1, Q2 FETs are 2.5V-to-3.3V I2C bus level shifters between the original Omega and the OLED display controller.
Q1, Q2 are 3.3V-to-3.3V I2C bus "level shifters" between Omega2 and the OLED display controller.

Omega2 has I2C, SPI and serial interfaces so theoretically you could connect it to any display that has one of these interfaces.
Unfortunately only the OLED Expansion has full (out-of-the-box) Onion software support.

Ok, thanks György
Just for clarity, if I use a 3,3V I2C slave device with Omega2, I not need the two translator fets in addition to pull-up res, right?
Do you know what display controller is inside the OLED Expansion? Or which Manufacturer/model is the OLED module?

Please, another small question.
I see in the Oled expansion schematic (https://github.com/OnionIoT/Onion-Hardware/blob/master/Schematics/Omega-OLED-Expansion.pdf)
that the SCL and SDA lines are not directly connected between Omega2 module and display, but there are two mosfets.
What is the need of two additional components?
There are another type of display that I can connect to Omega2 and that are already supported with software?
Or, If connect to Omega a LCD I2C display with UC1601S controller, is easy for my "informatic colleague" to write code to control it?
What type of controller is inside the Onion Oled expansion module?
Thanks to all.

Very good, thanks.

Hi, I've never used an Omega and I've never written here, I write from Italy.
I'm developing a project considering an Omega2 module.
I plan to connect a Microchip MCP3008 ADC to the SPI bus
I read in the document "Using GPIOs" in the chapter "Important & Special pins" that at boot the pins GPIO6, GPIO7 and GPIO8, which is part of the SPI interface, should be left disconnected.
But how would it be possible to use an SPI device if it has to be unplugged at boot? Who will then link it into a forgotten box?
The pins mentioned should all be connected to the input pins of the MCP3008, could it still be a source of boot problems?
Any other warnings or suggestions on aspects that I missed?
Thanks.
Paolo.