LCD project not displaying

I’d suggest that you post the “hello world” sketch that worked, and if possible post a link to the LCD library that you’re using.
As I said earlier, each library has its own set of commands, and without understanding what your library requires it’s impossible to know if anything is missing from your code.


I have successfully used this LCD library with past Blynk projects and same (as OP code above) Widget to LCD commands, although I used Terminal at the time.


This is the " hello world " sketch im using earlier .

[Unformatted code removed by moderator]

This is the link for the Liquid Crystal library :

@Syed_Fitri please edit your post, using the pencil icon at the bottom, and add triple backticks at the beginning and end of your code so that it displays correctly.
Triple backticks look like this:


Dude… change to the library I already referenced… I tried many and that one is known to work with Blynk.

And BTW… backticks… not commas or quotes…

They also work best when the on their own lines, not in front or after other code on same line.

And for the initial set of backticks, follow up with cpp as that helps with formatting certain types of code as well.

Blynk - FTFC

To save my sanity as some of these topics drag on :stuck_out_tongue: … this code worked for me… adjust for your LCD size and naming preferences, etc. as you need

// ----- Liquid Crystal I2C Display
// OneWire
#include <Wire.h>
// main hd44780 header
#include <hd44780.h>  //
// i2c expander i/o class header-  Extensible hd44780 LCD library
#include <hd44780ioClass/hd44780_I2Cexp.h> 
// declare lcd object: auto locate & auto config expander chip
hd44780_I2Cexp PLCD; 
// LCD size
const int LCD_COLS = 20;
const int LCD_ROWS = 4;
void setup() {
  PLCD.begin(LCD_COLS, LCD_ROWS); // Start Physical I2C LCD
  PLCD.clear();  //  Clear the Physical LCD screen
// and so on
//===== Terminal Input =====
BLYNK_WRITE(V1) { // Terminal Input Function
  Serial.println("Terminal Input");
  String Termtext = param.asStr();
  PLCD.setCursor(0, 2);
  PLCD.print("                    ");  // Erase old text
  PLCD.setCursor(0, 2);
  PLCD.print(Termtext);  // Terminal Input on LCD Widget
} // END Blynk Function

:rofl: :rofl: :rofl:

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could you explain , what this code do . im so sorry , im still new in blynk and arduino .

Your “Hello World” sketch has this line (above) in setup() . . . Your Blynk sketch does not . . .

Add lcd.init(); to setup() in your Blynk sketch, try that,


It is everything you should need for the LCD setup with a “known to work with Blynk Library”. Just add to your basic Blynk sketch.

If you don’t understand this, then might I suggest starting off with much simpler projects?

Actually the project have been sent to my supervisor , and yeah I have a backup plan , but not with the LCD , so thank you for your help

You still haven’t fixed the formatting of your “hello world” code.
It will be deleted soon if you don’t fix it, as will other Unformatted code that you post in future.
We give people the benefit of the doubt when that don’t follow the instructions about posting code that glare provided when they creat a new topic, and two of us have asked you to fix the code formatting but you haven’t.
It’s a simple rule of the forum that you need to follow.


i will edit it asap , im in class , thank you pete

You had a go at editing the code, but I’m sure you could tell that it wasn’t formatted correctly, so I’ve deleted it.
If you wish to repost it then simply edit the post and paste the code in between triple backticks, but without any other formatting characters.

However, @Bill_Donnelly has already pointed-out why the ‘hello world’ sketch worked and your Blynk sketch doesn’t, so you know the answer to your problem.