There is a I2C backpack.
Thanks for the information, I had trouble with the cheapest 5V displays at a slightly lower voltage. Good to know that the HD44780 can operate at lower voltages.
I agree, but I first want to make a good match on the I2C bus, and then lower the impedance of the I2C bus and get closer to the maximum of 3mA sink current.
I don't know the Wire library of the STM32 branch and how it can recover from I2C bus errors.