Hi there,
I'm trying to understand how the wiring for the 1.8" TFT LCD breakout works, and the D/C pin is confusing me greatly.
My understanding of SPI is that you need the clock (SCK), a data pin for the Arduino to send data (MOSI), a data pin for the Arduino to receive data (MISO), and a chip-select pin for each peripheral (TFT_CS and CARD_CS).
Given that, I'm really confused what the D/C pin on the breakout board is for.
I notice that Adafruit's Micro SD breakout board has CLK, DO, DI, CS pins, which maps fine to my understanding of SPI. So what I'm wondering is if the D/C pin is actually a MOSI pin for the TFT, to keep it separate from the SD card's MOSI pin, for some reason? If that's the case, is there any reason they couldn't both be tied to the same pin on the Arduino?