The driver chip, SSD1306 can communicate in multiple ways including I2C, SPI and 8-bit
parallel. However, only the 128x64 display has all these interfaces available. For the 128x32
OLED, only SPI is available. Frankly, we prefer SPI since its the most flexible and uses a small
number of I/O pins so our example code and wiring diagram will use that.
© Adafruit
Industries
http://learn.adafruit.com/monochrome-oled-breakouts
Page 4 of 22