ILI9341 why 5th pin needed?

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1

I got a ILI9341 based TFT LCD module. All descriptions of this say you need 4 pins to drive it and it makes sense for standard SPI (MISO,MOSI, CS and CLK). But every single library (including Adafruit) I find requires 5th pin (DC). Anyone knows why? :slight_smile:

2

Look here (pg11) D/CX: This pin is used to select “Data or Command” in the parallel interface or 4-wire 8-bit serial data interface.

3

Thanks I see. So when they say in the product description "it only requires 4 I/O ports" they are outright lying? :slight_smile:

4

If you do not need to read from TFT (like status registers or pixel color) then you can omit the MISO pin.

5

MarekB:
If you do not need to read from TFT (like status registers or pixel color) then you can omit the MISO pin.

Aha! That's the info I was looking for! Thanks a lot!