LCD over 8bit 16it or SPI ?


I want to start a project with will involve displaying by arduino data on 320x240 pix LCD.

My LCD have three types of connection (8bit, 16bit, SPI).

Which conection will be most propriate ? I want to display some static pic + some text on it. Which interface from above is quicker ?

Could you post the spec sheet of your display? I am guessing SPI might be best and saves pins on your arduino, especially if you are already using other SPI devices such as ethernet or sd card. I bet you will likely use sd card to store images since your display has a high resolution (compared to Arduino's FLASH.

SPI will be the simplest interface by far, if that's available to you. Note, though, that most of the LCDs I've messed with to date have not had an 8-bit SPI interface (9-bit seems to be pretty common), meaning that you need to bit-bang at least one bit of the transmission (rather than letting the hardware SPI interface handle all of it for you), and control the CS pin manually.

8- and 16-bit interfaces (sometimes referred to as DBI in data sheets; it's a parallel interface) will typically suck up a huge number of pins; not necessarily a problem with the Mega, but can be a burden on a standard-footprint Arduino. Done correctly, these interfaces can be faster.

But, I agree with liudr: a data sheet would mean we could give you more specific answers.

This LCD has indeed build-in SD card reader which I wanted partially use to store images, partially to permanent store data collected by arduino.

I would prefer to use SPI (so I will have more pins available for other extensions) but I also want LCD to refresh with decent speed, to not get some flickering images.

As for LCD manufacturer it is hard to determine but I can tell you few details of it:

LCD controller is LGDP 4531
Touch Screen controller ADS7843
Built-in SD card socket.
There is also place for AT45DBxxx memory, but I do not plan to use it in near future (instead I want to attach EEPROM to I2C bus with some other parts).

I don’t know if this is necessary but If you want to see it, here is some pics:

In this project arduino will have to collect some data form ‘external sources’ and then store data to SD card and display information about gathered data to LCD.