I'm working on this piano project. When I push a button one of the led light is suppose to turn on and a tone comes out of the piezo. The LCD screen is suppose to print out a sentence but I can't get it to work.

Here is a picture of the board ( everything works except the LCD) I think the problems lies in the power supply but I'm not sure. This is the first time I use a big breadboard. Image of the board

Here is my code:

#include <LiquidCrystal.h>

LiquidCrystal lcd(13,12,11,10,9,8);

int p1 = 1; 
int p2 = 2;
int p3 = 3;
int p4 = 4;

int C,D,E,F;  
int buzz = 5;

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

  lcd.print("hello, world!");



void loop()

  lcd.setCursor(0, 1);

  lcd.print(millis() / 1000);

  C = digitalRead(p1);
  D = digitalRead(p2);
  E = digitalRead(p3);
  F = digitalRead(p4);

  if(C == 1){ 

  }else if(D == 1){
  }else if(E == 1){
  }else if(F == 1){

  • 3
    the power rails are separated in the middle of the breadboard. bridge them with jumper wires
    – Juraj
    Apr 17, 2019 at 13:57
  • 1
    According to the picture, RS and E are connected to pin 8 and 9. According to your sketch, RS and E are connected to 13 and 12.
    – Jot
    Apr 17, 2019 at 15:42
  • Did you set the contrast correctly (using the potentiometer)?
    – Gerben
    Apr 18, 2019 at 8:58

2 Answers 2


The LCD is not powered, there are 2 separated power rails... use a wire to connect both rails.

  • Where do I put the wires?
    – Chase
    Apr 17, 2019 at 16:42
  • You need to use a wire to connect the 2 rails. Right where is the bigger separation. Apr 17, 2019 at 19:22

the power rails are separated in the middle of the breadboard. bridge them with jumper wires

enter image description here

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