(Solved) Weird Characters on LCD Screen Driving me mad!

[LearningtoCode]

Good evening,

Please could someone help. I have been wiring up a 16 x 2 LCD screen with an Arduino Uno and trying various code. At first I got on really well and it was doing exactly as I wanted, learning the code well. then yesterday the screen started showing unusual characters.

I have re-wired it numerous times to ensure that I have done it exactly as it is meant to be. And I have taken the code back to basics but it is still causing the same issue.

I have even bought another LCD screen just in case it was that.

Here is the code: -

#include <LiquidCrystal.h>
LiquidCrystal lcd(12,11,5,4,3,2);


void setup() {

  lcd.begin(16,2);

}

void loop() {
  // put your main code here, to run repeatedly:
  lcd.begin(16,2);
  lcd.setCursor(0,0);
  lcd.print("Hello");
  delay (500);

}

I have also attached a photo for reference.

Hopefully someone will be able to assist.

Thanks.

[LarryD]

To start, your header soldering needs to be re-flowed.

[BulldogLowell]

LearningtoCode:
Here is the code: -

void loop() {

// put your main code here, to run repeatedly:
  lcd.begin(16,2);
  lcd.setCursor(0,0);
  lcd.print("Hello");
  delay (500);

}

why are you calling begin() every time through loop()?

set it in setup() and forget it!

[anon57585045]

LarryD:
To start, your header soldering needs to be re-flowed.

+1. Look at the fourth one from the right. It has barely any solder on the actual join.

[econjack]

This might be some other issues, too, since "Hello" does not appear in the correct row-column position. What happens with this code:

#include <LiquidCrystal.h>
LiquidCrystal lcd(12,11,5,4,3,2);


void setup() {

  lcd.begin(16,2);

  lcd.setCursor(0,0);
  lcd.print("                ");    // 16 spaces
  lcd.setCursor(0,1);
  lcd.print("                ");

}

void loop() {
  int i;

  for (i = 0, i < 11; i++) {
    lcd.setCursor(i,0);
    lcd.print("Hello");
    delay (1000);
    lcd.setCursor(i,0);
    lcd.print("                ");    // 16 spaces again
 }
}

[system]

Try this , eliminates some redundant coding

#include <LiquidCrystal.h>
LiquidCrystal lcd(12,11,5,4,3,2);


void setup() {
  // initialize and clears LCD 
  lcd.begin(16,2);
 delay (5000); // is the display clear for 5 seconds ?
}

void loop() {
  // put your main code here, to run repeatedly:
  lcd.clear(); // clear display 
  lcd.print("Hello");// writes to line 0, position 0
  delay (5000); // show hello for 5 seconds 
lcd.clear(); // clear display 
  lcd.print("The quick brown fox jump over the lazy dog  1234567890" // writes to line 0, starting position 0 uses most ASCII printable characters and may not write all of them on LCD or overwrite some
  delay (5000); // show it for 5 seconds 

}

[LearningtoCode]

Hi all,

Thank you for the responses so far.

I have just quickly touched up some of the soldering and also tried the code above but it is still not working. I tried with both screens to see if it made a difference but neither are showing what they are meant to.

Se attached photos.

[LarryD]

What does +5v read at the LCD?
With the power off, check the resistance from each pin at the LCD to the corresponding ARDUINO header pin.
The contrast could be lowered.

[econjack]

Have you tried using different pins for the display, like:

LiquidCrystal lcd(12,11,7,6,5,4);

Next, can you test the code on a different Arduino? Finally, do you know that the display works with this LiquidCrystal library? (I think there is more than one LiquidCrystal library.)

[LearningtoCode]

LarryD:
What does +5v read at the LCD?
With the power off, check the resistance from each pin at the LCD to the corresponding ARDUINO header pin.
The contrast could be lowered.

I will give this a go when I get home this evening.

econjack:
Have you tried using different pins for the display, like:

LiquidCrystal lcd(12,11,7,6,5,4);

Next, can you test the code on a different Arduino? Finally, do you know that the display works with this LiquidCrystal library? (I think there is more than one LiquidCrystal library.)

I do have an Arduino Micro which I have tried it with but am still getting the same problem. I will try testing the different pins when I get home. Now that is an interesting question with the library. The library was for the first LCD screen I had, although I have bought a similar screen (both 16 x 2 LCD's) I am not sure it is correct, I just assumed it would be. How could I check this?

[LearningtoCode]

econjack:
Finally, do you know that the display works with this LiquidCrystal library? (I think there is more than one LiquidCrystal library.)

Thank you!

I have solved it with.... https://learn.sparkfun.com/tutorials/oled-display-hookup-guide/firmware

Being a beginner I didn't realise an OLED display was different. It has to be wired differently and use a different Library.

Thank you all for your responses.

[kr_alexander]

Thank you ! Solved at least my problem !