Hi. I recently bought the following ST7796S based display for use with Uno or Mega. http://www.lcdwiki.com/3.95inch_Arduino_Display-UNO. Downloaded and installed the relevant LCDWIKI libraries and examples. I am using with a Mega2560.
Was able to successfully run the _ST7796S_Mega2560.ino example sketch which doesn't use the LCDWIKI libraries. When I tried running the other examples which make use of the libraries, all I achieved was a white screen. I have examined all the supplied library files and have a fairly good understanding of how they work.
I notice that in the file lcd_mode.h there is the following macro.
define USE_8BIT_SHIELD_ON_MEGA 0 which should be commented out according to the comments.
There is also a line in the file LCDWIKI_KBV.h //#define USE_ADAFRUIT_SHIELD_PIN 1 which I believe should be uncommented. If I change either of these lines from the default I get a massive amount of errors when compiling.
I feel I have spent more than enough hours trying to solve the problem and would rather work on the application that I bought the screen for. Would be grateful if someone could advise me of the modifications I need to the library files. Even better would be if someone who has had success with this display could upload a fully functional program that uses all of the displays features including touch & sd card functions, along with the modified library files.