LCD Wont Display "Hello World"


Im working with a 16x2 LCD screen purchased from a sunfouder super Kit.


Ive tried several of the other threads involving LCD’s not printing out “hello World”, but I have had no luck. I have attached a picture of my setup. The LCD does turn on and display white blocks across the bottom row. I can adjust the contrast of the blocks with the 10K pot, but when I program the arduino with the code below, the bottom row disappears and when i adjust the pot the text still doesn’t appear.

// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("hello, world!");

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
   print the number of seconds since reset:
  lcd.print(millis() / 1000);

Please Help!!



. . . The LCD does turn on and display white blocks across the bottom row. . . .

Aside from the fact that your setup is upside down everything looks OK to me. Of course my eyes are pretty old, maybe someone else will spot something I missed.

You might want to check out the integrity of your white jumper wires. The others are good, otherwise you wouldn't be able to see the white blocks.

If you do not have an ohmmeter you can just replace the red wire feeding your backlight (LCD pin 15) with each of the white wires, one at a time, and see that the backlight still works with all of them.


Like Don, I can't see anything mis-wired. If testing/changing the jumper wires does not fix your problem, you might try moving the display and wires to a different set of holes in the breadboard. I have seen defective locations in some of mine.

Is the red wire connecting the breadboard to the Uno going into the Uno 5V or the 3.3V? The display requires 5 volts.

The display requires 5 volts.

The display was functioning since he could see the white blocks.

Your question points out the need for photos taken from farther away to minimize parallax.



Can’t see the problem but just mentioning - if resistor R8 on the LCD module is “101” or 100 Ohms, then the extra resistor on the LED supply is superfluous.