I've had some limited success and ruled out some things.
- Using this modified UTFT library, I was able to get the display to display something. It ran the tests as shown, but was very slow and the colour were wrong and grainy, and the display was shifted by some number of pixels both horizontally and vertically
- Cannot get either the smaller display to work on the Mega or the larger display to work on the Uno, trying all manner of driver and library combinations
The modified library appears to use an 8-bit version of the ILI9327 driver normally found in the UTFT library. This is consistent with what the display seller claims (that it has an ILI9488 chip and to use ILI9327 drivers). On an email request, the seller sent me a zipped folder with code that produces the same result as the above library, but hard-coded in the example instead of in a library. The zip foile also contained a video that shows screen capture of someone loading UTFT, hinting that the above would work, but is useless aside from that.
Now, I've read further on the subject, and speed seems to be an issue on the Mega due to pin/port mapping being slow. I understand this, but example videos on youtube show a working example of this type of shield (perhaps a different chip) on a Mega running the UTFT display tests at "full speed" without any colour distortion. Does anyone have any insight into this? I understand I may need to make rotation adjustments, but the colour and whatnot needs to be correct first.
Lastly, can anyone confirm that my issues would just disappear if I were to buy another similar display that uses the back row of pins on the Mega? Does this change how mapping works? Would the different pin arrangement necessitate a different chip and driver, and thus make the libraries work without hacking them up?
See the attached image.