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Today I tried to display some text with my Arduino UNO and a LCD 1602A screen. I did find some schemas online, but I cannot get any character or "black boxes" on the display.

I connect wires like that : Pin 1 : GND Pin 2 : +5V Pin 3 : 50K Pot. Pin 4 : Pin 7 from Arduino Pin 5 : GND Pin 6 : Pin 6 from Arduino Pin 11 : Pin 5 from Arduino Pin 12 : Pin 4 from Arduino Pin 13 : Pin 3 from Arduino Pin 14 : Pin 2 from Arduino Pin 15 : +5V Pin 16 : GND

You can see my setup here : http://imgur.com/a/QkI4z

The LCD screen is lighten up, but nothing else appears. Pot. is working (increase or decrease light). I tried to change the LCD with another, but both are not working. I tested some many code, here an example :

/*
  LiquidCrystal Library - Hello World

 Demonstrates the use a 16x2 LCD display.  The LiquidCrystal
 library works with all LCD displays that are compatible with the
 Hitachi HD44780 driver. There are many of them out there, and you
 can usually tell them by the 16-pin interface.

 This sketch prints "Hello World!" to the LCD
 and shows the time.

  The circuit:
 * LCD RS pin to digital pin 12
 * LCD Enable pin to digital pin 11
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * LCD R/W pin to ground
 * LCD VSS pin to ground
 * LCD VCC pin to 5V
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)

 Library originally added 18 Apr 2008
 by David A. Mellis
 library modified 5 Jul 2009
 by Limor Fried (http://www.ladyada.net)
 example added 9 Jul 2009
 by Tom Igoe
 modified 22 Nov 2010
 by Tom Igoe

 This example code is in the public domain.

 http://www.arduino.cc/en/Tutorial/LiquidCrystal
 */

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

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

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):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis() / 1000);
}

Do you have an idea ? Thanks !

  • 1
    Looks like your pot is wired wrong. It should be between VEE and GND with the wiper to VO, not between +5V and GND. – Majenko Aug 5 '16 at 10:44
  • Sorry to ask, but what's VEE ? – Treast Aug 5 '16 at 15:14
  • Actually, ignore that - I am thinking graphical LCDs that have a different offset voltage requirement. – Majenko Aug 5 '16 at 15:16
2

I realize that your question is based around using multiple connections to the arduino, however if you wish to simplify the setup/operation have a good look into I2C interface, this only uses 2 pins SDA and SCL to operate, you can get an interface board on Ebay for $1.00....just a thought.

1

Wiring on the photo and description you provided are not consistent. On the photo, LCD-RS (PIN 4) is connected to D12 and LCD-E (PIN 6) is connected to D11?

If so, initialization must be LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

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