I've tried this code on an LCD, and instead of displaying "Hello World!" it displays what is shown on the picture.


#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);

void loop() {
  lcd.print("Hello World!");

Photo of LCD displaying corrupted text

  • 2
    You probably listed the wrong pin numbers in LiquidCrystal lcd(12, 11, 5, 4, 3, 2); but haven't supplied a wiring diagram so who can say. – James Waldby - jwpat7 Jun 3 '17 at 20:49
  • I've doublechecked the wiring – Guilherme Peralta Jun 3 '17 at 22:38
  • 1
    Sure, the wiring may be fine ... but you might have the wrong numbers within lcd(12, 11, 5, 4, 3, 2), or have them in the wrong order – James Waldby - jwpat7 Jun 4 '17 at 1:06

Try the following

  1. Double-check the LCD soldering
  2. Double-check your wiring

  3. Ensure that the pins you are using for your LCD are not assigned to some other function. This caused jumbled, random characters here.


From the attached I can see that you are connecting D7 to digital 2 of arduino. And I assume the pins D6 D5 D4 are also connected to 3, 4, 5 pins respectively, which is correct for your code. But make sure the R/W pin is connected to proper ground. Verify that by measuring voltage if possible. Also serial print whatever you are giving the lcd to make sure it is not an encoding issue.


Don't take this the wrong way but some of those solder joints looks a little rough. I'm not sure this is your issue but you need some soldering practice. Solder joints should be bright and shiny and should completely cover the pad.

I can tell by the joint on pin 16 you didn't get it hot enough or the solder would have flowed to cover the entire pad. Some of the other joints look like they were overheated. Does your soldering iron have a temperature control? Experience will help you know when to turn it up and when you can get by with a lower temperature. Is your tip too large or needs replacing?

There's lot's of soldering how-to videos out there but no substitute for practice, practice, practice and then practice some more. :)

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