Level shifting 3.3v to 5v only RX and TX pins

Good night, I'm trying to solve a voltage problem in my project ...

Currently I changed my Arduino MEGA (5v) for an Arduino DUE (3.3v), I made all the adjustment of the sensors and etc (none needed a level shifter), however my display a Nextion 3.5 "works in 5v and I am trying to make the pins RX and TX work in 3.3v.

Here is the connection scheme I made:

But the Display does not respond to my commands, I tried to use this line:

void setup()
{
Serial2.begin(9600);
}

void loop()
{
Serial2.print("page carregamento");
Serial2.write(0xff);
Serial2.write(0xff);
Serial2.write(0xff);
delay(2000);
}

This code worked when I used it in 5v, so the problem is not the code but the connection ...

So I thought of the hypothesis that the logical converter had to be energized, so I tried to call it this way:

But it also did not work ...

The display is on normally, but communication between the display and the arduino is zero ...

What am I doing wrong? Thank you.

Where is your Serial2.begin() statement in setup?

Without calling begin, passing the baud rate as it’s argument, serial communications will never work.

DrAzzy:
Where is your Serial2.begin() statement in setup?

Without calling begin, passing the baud rate as it’s argument, serial communications will never work.

That’s true!! I forgot to wrote this part of code… Thanks a lot.

The wiring of the level shifting board is incorrect. Here are the correct connections:

Arduino1.png

WattsThat:
The wiring of the level shifting board is incorrect. Here are the correct connections:

Arduino1.png

It worked!!! Thanks a lot…

And a another question, why I’ve to supply to HV and LV and not only one of them?

Without the 3v3 supply, the RX line into the Due will not function.

Level shifter needs both of the voltages it is shifting between (in a very broad sense, how else would the level shifter "know" what voltage to shift to/from otherwise?)

I got it! Thanks a lot for your help guys... Closing this thread, problem solved.