PIC12F675 uses software I2C to drive the OLED display. The PIC ADC reads analogue input of 0-5 Vdc. Reading updated every 500 msec.
Details
The downloaded code is for 0.96 inch OLED 128x64, to use 0.91 inch OLED 128x32 one line in the code has to be changed as the instruction in the code file.
Yes Clovis, click download in "files" section above.