I wired correctly the SSD1306 to my Orange Pi 5 with Diet Pi v8.15.2 and nothing happens… I searched in dietpi-launcher to enable i2c …but I don’t find it. Did someone have similar issue? Thanks in advance 
You can activate i2C in dietpi-config → advanced options.
And maybe you also need a driver like https://github.com/lexus2k/ssd1306
is maybe related to Radxa source kernel modules? I found this Add missing I2C, SPI, PWM, UART, LCD overlays to Orange Pi 5 by efectn · Pull Request #4712 · armbian/build · GitHub
The availability of options depends on SBC used. They are not the same on all devices. I guess something @MichaIng could support with.
Check the available overlays in /boot/dtb/rockchip/overlay. Those with rockchip-rk3588- prefix can be added to the overlays= line in /boot/dietpiEnv.txt without the prefix and file ending. Indeed the PR you linked added a bunch of additional overlays, and those are available with current kernel package already. Looks like you can now follow the instructions you posted, just additionally prepending each overlay with opi5-:
overlays=opi5-i2c1-m2 opi5-i2c3-m0 opi5-i2c5-m3
Not sure about the difference between i2c1-m2 and i2c1-m4 here, or in which case to use which of them.
Okay great. And i2c1-m2 enables I2C1 on different pins, or have the same pins different identifies on different board revisions?
good question because I only see for m0, m3 and m4. Unless it was different for v1.0… now the problem is that all drivers have some problem because in some the board is not detected. If Raspberry Pi no problem but for Orange Pi 5 no luck yet in my research 
Edit: Luma drivers work in Orange Pi 5. I followed the next video of YouTube and works all. I tried all options and only this one worked for me with Luma. Hope it helps to peopple who wants this OLED to Work with DietPi and Orange PI 5.
