Require help with failing LCD project

Using Arduino Displays
#1

Hello! I’m having a bit of trouble with my project. It’s Project 23 from “Arduino Basics” by Michael McRoberts. Only the backlights of the LCD are functioning, and I haven’t been able to make it write. Here’s the code:

#include <LiquidCrystal.h>


LiquidCrystal lcd(12, 11, 5, 4, 3, 2); 


void setup() {
  lcd.begin(16, 2);
}

void loop() {
  
basicPrintDemo();
displayOnOffDemo();
setCursorDemo();
scrollLeftDemo();
scrollRightDemo();
cursorDemo();
createGlyphDemo();
}

void basicPrintDemo(){
lcd.clear(); 
lcd.print ("basic print");  
delay(2000);
}

void displayOnOffDemo(){
  lcd.clear();
  lcd.print ("display On/Off"); 
for (int x=0; x<3; x++){
lcd.noDisplay();  
delay(1000);
lcd.display();   
delay(1000);
}
}

void setCursorDemo() {
lcd.clear();
lcd.print ("Set Cursor Demo");
delay(1000);
lcd.clear();
lcd.setCursor(5,0);
lcd.print ("5, 0");
delay(2000);
lcd.setCursor(10, 1);
lcd.print ("10, 1");
delay(2000);
lcd.setCursor(3, 1);
lcd.print ("3, 1");
delay(2000);
}


void scrollLeftDemo() {
  lcd.clear();
  lcd.print ("Scroll Left Demo");
  delay(1000);
  lcd.clear();
  lcd.setCursor(7,0);
  lcd.print("beggining");
  lcd.setCursor(9,1);
  lcd.print ("Arduino"); 
  delay(1000);
  for (int x=0; x<16; x++) {
    lcd.scrollDisplayLeft();  
  delay(250);
  }
}
void  scrollRightDemo(){
  lcd.clear();
  lcd.print ("Scroll Right");
  lcd.setCursor (0, 1);
  lcd.print ("demo");
  delay(1000);
  lcd.clear();
  lcd.print("beggining");
  lcd.setCursor(0,1);
  lcd.print ("Arduino"); 
  delay(1000);
  for (int x=0; x<16; x++) {
    lcd.scrollDisplayRight(); 
  delay(250);
    }
  }
  void cursorDemo() {
    lcd.clear();
    lcd.cursor(); 
    lcd.print ("Cursor On");
    delay(3000);
    lcd.clear();
    lcd.noCursor(); 
    lcd.print ("Cursor Off");
    delay(3000); 
    lcd.clear();
    lcd.cursor();
    lcd.blink(); 
    lcd.print ("Cursor Blink On");
    delay(3000);
    lcd.noCursor();
    lcd.noBlink();
  }
void createGlyphDemo() {
lcd.clear();

byte happy[8] = { 
  B00000,
  B00000,
  B10001,
  B00000,
  B10001,
  B01110,
  B00000,
  B00000};

byte sad[8] = { 
  B00000,
  B00000,
  B10001,
  B00000,
  B01110,
  B10001,
  B00000,
  B00000};

  lcd.createChar (2, happy);
  lcd.createChar (1, sad);
   for (int x=0; x<5; x++) { 
    lcd.setCursor(8,0);
    lcd.write(2);               
    delay(1000);
    lcd.setCursor(8,0);
    lcd.write(1);                  
    delay(1000);
   }
}

Here are some pictures of how everything is set up, I believe it complies to the code:

I hope they are sufficient to decipher the mess of wires that’s going on down there :grin:

The LCD screen is a qapass 1602a. Has required by the book this experiment is from, I’m using a 10k ohms resistor for the contrast, but for the Vee pin I’m using a 270R resistor (the book gives you no guidance on that regard). Maybe that is the issue? I would appreciate assistance.

#2

Your program is too ambitious for a first attempt. Try something simple first.

#include <LiquidCrystal.h>

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);       // put your pin numbers here

void setup()
  {
  lcd.begin(16, 2);                          // put your LCD parameters here
  lcd.print("hello, world!");
  lcd.setCursor(0,1);
  lcd.print("it works!");
  }

void loop()
  {
                                             // do nothing in 'loop'
  }

Your pictures are a bit hard to see.

I don’t have the book, and most of the readers here probably don’t have it either.

Don

#3

floresta:
Your program is too ambitious for a first attempt. Try something simple first.

#include <LiquidCrystal.h>

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);      // put your pin numbers here

void setup()
  {
  lcd.begin(16, 2);                          // put your LCD parameters here
  lcd.print(“hello, world!”);
  lcd.setCursor(0,1);
  lcd.print(“it works!”);
  }

void loop()
  {
                                            // do nothing in ‘loop’
  }





Your pictures are a bit hard to see.

I don't have the book, and most of the readers here probably don't have it either.

Don

Thanks for the help Don. Sorry for the late response. Apparently the problem was that the “RW” LCD pin needed to be connected to GND. This was not indicated anywhere in the book.

#4

The same omission from the tutorial was a big problem that was fixed many years ago, probably close to a decade. Your 'book' is probably derived from the ancient tutorial.

Don

#5