Arduino with LCD Issues

I recently bought an Arduino micro, a generic 16x2 LCD, and some other stuff. When I try to power up the LCD, nothing happens.

I am using the Hello world example already in the editor. To my best knowledge, all the connections are the same as in the example.

I have a basic understanding of electronics. I am really confused right now, thanks in advance for the help!

(Heres the code I am using, just in case you need it.)

/*
  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
 modified 7 Nov 2016
 by Arturo Guadalupi

 This example code is in the public domain.

 http://www.arduino.cc/en/Tutorial/LiquidCrystalHelloWorld

*/

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

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

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);
}

If it doesn't work, it has to be some misconnections. You may need to review the instructions again and examine some of the error wirings.

I have already checked and rechecked the connections, and they seem to be going to the right pins. Unless I have some bad wires, I don't think this is the issue.

turn the pot. let see some dots and adjust until you almost see them.

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Many of those 'longer' breadboards power rails are not continuous from end to end. To make the power rails end to end a jumper needs to be placed across the middle pins.


The red line represents a break in the power rails that need to be jumpered if the power rail is to be from end to end.

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or you can check with a DVM to confirm if you got 5 V at the pot, the LCD display.

BINGO..
bingo

Tom... :smiley: :+1: :coffee: :australia:

I believe that gap is there because I am operating the LCD in 4-bit mode

No the gap is because that is how the protoboard is constructed.
You need to put jumpers across each of the breaks so each side has a continuous connection.

Do you have a DMM?
How do you think the LCD module gets its power?

Tom... :smiley: :+1: :coffee: :australia:

So every single one of those breaks needs a jumper across?

Yes if you are using them.
Not difficult to do.

Tom... :smiley: :+1: :coffee: :australia:


(added green and brown jumpers

IN the center of your breadboard there is a small gap that runs the length of the breadboard and that seperates one side from another. Is your LCD screen pins on one side of this gap and your jumper wires for your pins 1-16 of your lcd on the other side of this gap?

I do not have a dvm. Would the analog pins on the Arduino work?

Well in that case, just turn the pot to check if any dots show up. If yes, than the LCD is working.

Have you tried what @sergetechone said about the contrast pot on the back?

No (sorry for the terrible photos guys, I'm using my laptop camera...)

yes I have been twisting that thing every time I try something new

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Just going to ask, but i dont see a power source in the pcicture. You are powering the circuit correct?

Yes, with a USB micro power cord from my laptop. the blue light under the Arduino turns on