My adventure into I2C devices over HDMI after running set up script, you are in i2c group, but .. theres a glitchy thing, might need need to log out and back in, though you are now member to the i2c group. as a member to the i2c group, with group ownership over the i2c devices, you should not need root to run programs accessing the i2c bus. thats the thought anyway.
STEMMA 4-Pin I2C (both standard & STEMMA QT)
Black for GND.
Red for V+
Blue for SDA.
Yellow for SCL
I just obsurved a singular device with several addresses, might try to write that into a serach option.
LCD 16x4, i2c base addresses, 0x20 thru 0x27
I had been messing with this on a display port to HDMI addapter, and could not get it to work. When I switched over to a straight throught HDMI, it worked instantly!
sudo apt-install python3-dev pip install spidev