Using LCD TFT LMT035DNJFWD

Projects Programming
1

Hello All ,
Pleas I have LMT035DNJFWD-NAN LCD 3.5'' TOPWAY display
I want just to test it and write text . I connected
RD - A0
WR - A1
RS - A2
CS - A3
RST - A4
D0 - 8
D1 - 9
D2 - 2
D3 - 3
D4 - 4
D5 - 5
D6 - 6
D7 - 7

and this is the code , but nothing appears on the screen , please help




#include <Adafruit_GFX.h>

#include <Adafruit_TFTLCD.h>




//SPI Communication
#define LCD_CS A3
#define LCD_CD A2
#define LCD_WR A1
#define LCD_RD A0
// optional
#define LCD_RESET A4

//Color Definitons
#define BLACK     0x0000
#define BLUE      0x001F
#define GREY      0xCE79
#define LIGHTGREY 0xDEDB
#define RED     0xF800
#define GREEN   0x07E0
#define CYAN    0x07FF
#define MAGENTA 0xF81F
#define YELLOW  0xFFE0
#define WHITE   0xFFFF



Adafruit_TFTLCD tft(LCD_CS, LCD_CD, LCD_WR, LCD_RD, LCD_RESET);


void setup() {
  Serial.begin(9600);

  tft.reset();
  uint16_t identifier = tft.readID();
  tft.begin(identifier);

  //Background color
  tft.fillScreen(GREEN);

  // draw num pad

  


}

void loop() {


  
    //redraw numpad to clear old number
    tft.fillScreen(GREEN);
   
    //default text setup for number display on tft
    tft.setCursor(100, 120);
    tft.setTextColor(RED);
    tft.setTextSize(9);
    tft.println("5555555555555555555555");
    

    // good for debuggin, prints out the x,y cordinates of the press
    // tft.setTextSize(10);
    // tft.print("X = "); tft.println(X);
    // tft.print("Y = "); tft.println(Y);

  }

Thanks
Amr

2

Please post a link.
Which exact board (Arduino, ...) are you using?

3

Hello

I m using arduino uno

Thanks

4

There were two questions :wink: You should answer both, else we have to guess. I did find a couple of Topway 3.5" displays (https://www.topwaydisplay.com/index.php/en/dosearch?keys=LMT035DNJFWD) and they are 480x320 pixels.

In which case I suspect that "Uno" explains it all as it does not have enough RAM to handle those displays.

6

Hello ,

I m sorry I was uploading the datasheet in another post but the internet connection went down :slight_smile:

This is the datasheet of the display i'm using

https://www.topwaydisplay.com/index.php/en/product/tft-lcd/tft-lcd-module-LMT035DNJFWD-NAN

Thanks

7

Hello [sterretje]

Could you pls help if you have any ideas or suggestions

Thanks

8

the LMT035DNJFWD-NAN LCD USER Manual states

  1. the TFT driver is a IL19488 or equivalent and gives information on the SPI interface pins - the TFT_eSPI library should be able to drive this display
  2. although VCC is 5volts the Input High Voltage (on SPI pins etc) is 3.3Volts MAX - do not connect it directly to microcontrollers such as the UNO which use 5volt logic - use level convertors or better a microcontroller which uses 3.3V logic, e.g. ESP32, RP2040, DUE, etc
9

Does that library work on an Uno?

10

I doubt it - I would try to avoid connecting such a display to a 5V logic system in particular low SRAM microcontrollers such as the UNO
such displays are tricky enough to get working without having level converters
the documentation does mention UNOs but in the context of ESP32 UNO style boards

11

Hello ,
Thanks all for reply , yes I noticed its logic is 3.3v , but do you think It may damage the display If I connected it to uno directly ? , Also if the tft_espi library doent work with it , is there another library that works? , this is the pin assignment

lcd
lcd572×552 117 KB

12

on a device which uses 3.3V logic unless pins are specified as 5volt tolerant the device can be damaged if 5V logic is applied
in practice 3.3V devices may work with 5V logic for an minute, an hour, a day, for ever or fail immediately - you don't know - use level converters or even better switch to a microcontroller which uses 3.3V logic

you could try the Adafruit libraries - however, as @sterretje mentioned in post 4, the UNO probably has insufficient RAM to support the display

13

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.