LCD WC1602A0 does not work


I bought 2*16 LCD WC 1602A. After loading even simple code, the LCD stays blanc. Checked several times connections. The panel is powered by the Arduino board (+5V) Do you have any ideas what might be wrong?

depends what you mean by blank, to test the display all you need to do is apply power to it an ground the contrast pin, this should give you at least a black bar across the top line, white if your using a blue display, beyond that a picture of the connected display & code would be usefull


After going thru the data sheet I got the bars in the top row ( as in the picture).

The connections are:

LCD - Arduino Board

1 - Ground
2 - +5V
3 - Potentiometer
4 - Pin 2
5 - Ground
6 - Pin D3

11 - Pin 4
12 - Pin 5
13 - Pin 6
14 - Pin 7

The test code:

#include <LiquidCrystal.h>
LiquidCrystal lcd (2, 3, 4, 5, 6, 7);

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

void loop ()
lcd.setCursor (0,1);
lcd.print (“Test”);
delay (2000);


have you grounded pin 5 R/W? I cant see it in the pic

If you insist on using the same colors for all of the data wires then you will have to spread them out so we can follow the original wires. Of course if the picture had higher resolution we might be able to follow what you have.

Why are you displaying non-changing information in 'loop'?



The LCD Pin 5 is grounded.

This is only test code, in this version I put the static info in the main loop, in other version this is indeed in the setup section. The result is the same i.e black bars in the top line.

When you get a single line of blocks it indicates that your LCD controller is not being initialized correctly. This is usually due to a problem with the wiring.

In order to help you we need a photograph that allows us to unambiguously follow each of the wires from the Arduino to the LCD module. We also have to be able to see all of the breadboard connections along with the quality of the soldering of the LCD pins.

In addition we need a copy/paste version of the complete code that you used.

A link to the LCD datasheet is frequently needed as well.