Arduino Mega with ILI9341 TFT screen

Hi,

I’m trying to make a chinese TFT screen work, I tried everything I found online with no results so I’m seeking the help of the community.

Parts:

LED and VCC to 3.3v, Arduino powered via USB from the computer.

The TFT screen says it’s 5v compatible but I read that sellers are lying so I got the logic converter, it never worked with or without it. Also the listing says ILI9341, I read seller are lying and it could be ILI9340, I tried both Adafruit libraries (https://github.com/adafruit/Adafruit_ILI9341, https://github.com/adafruit/Adafruit_ILI9340) graphictest examples.

I tried many combinations of pins for MISO, MOSI, CLK (13,12,11), then I read Mega uses (52,51,50) still no result.
I tried combinations of pins for DC, CS (6,5) (10,9) still no result.
I tried combinations of pins (13,12,11), then I read Mega uses (52,51,50) still no result.
I tried reset in pin 4 and 8, then I read it should be set to 3.3v but again no result.

I tried to connect MOSI directly to Arduino nothing, set LED to 7 nothing.

During all these test the screen was completely white.

Looking forward for any new ideas to try.

Many thanks.

Try using resistors as voltage level converters as described here.

Clearly you will use different hardware SPI pins for the Mega but the principles are the same.

bodmer:
Try using resistors as voltage level converters as described here.

Clearly you will use different hardware SPI pins for the Mega but the principles are the same.

Thanks for your reply, I don't think that's the issue, the logic converter is providing a perfect 3.3v better than what resistors would do.

OK, use an oscilloscope to view the SPI signals on the 3.3V side just to verify the level translator is doing what you think it is. You want to see nice fast edges and a clean clock signal reaching both a good logic 0 and a good logic 1. Make sure you have a common GND (0V) connected to both the display and the Arduino

Alternatively, if you do not have an oscilloscope, try using resistors, others have got this display working OK. See here.

You have to start trying something different until you figure out what is happening and what is not being setup correctly.

Thanks @bomer, turns out I was stupidly using the wrong pins, I thought pin Ax is pin x which is not.
Now it's working perfectly with the logic converter but not without it, using the Adafruit_ILI9341.

Many thanks.