So I’m looking at a 3.2" TFT touchscreen (http://www.ebay.com/itm/3-2-inch-TFT-LCD-module-Display-with-touch-panel-SD-card-240x320-than-128x64-lcd-/200908823757?pt=LH_DefaultDomain_0&hash=item2ec7195ccd) for a controller project.
I’d like to run the finished unit off of a atmega328, as I already have some lying around. The problem, however, is that this comes with a 16-bit parallel interface. Then there’s the touch pins, and the SD card pins (which I could live with out if I need to save pins). So between those it eats up pretty much all the pins on the 328.
I’m aware that the driver on it, the ssd1289, supports 3 and 4 wire serial. However, according to this Sprites mods - Connecting an LCD to a non-video-capable Linux device - Hardware, the boards do not bring the jumpers for the controller out to anything that can be used. So it’s stuck with the default 16-bit interface.
My next thought is to run it off a shift register, similar to how the guy in the spritemods link did it. I’m concerned, though, how slow the display would be. I’ve read people having it take 4 seconds to clear the screen in similar configurations. All I need it to do is display some text data streams, static images, and run a couple sliders. So my needs aren’t too demanding on it, so it might work this way.
The other plan is to run it off of an Chinese Mega2560 clone ($10 from ebay, just the atmega2560 uC is more than that everywhere I’ve looked) with the appropriate shield (another $7ish) .
So could I get some input on the pros and cons of each way of doing it? Or perhaps other solutions to the problem?