I have this SSD1306 OLED display, and I'm trying to figure how to connect it to my NodeMCU with SPI. It looks like this:
I browsed several sites, and I could see that the SCK is the clock, SDA is MOSI and CS is Chip Select, but I just couldn't figure out what is DC and RES. Everywhere I looked it just says to connect it to some pin or another (depending on the board in discussion). What is the SPI functions of those pins?