Hi all,
I am currently trying to light up a LCD screen with Arduino Uno just using the basic code from 'hello world' tutorial (https://docs.arduino.cc/learn/electronics/lcd-displays). But although the screen lights up, it does not show anything - no words, no symbols, no blocks. I have checked through the connections multiple times and have followed the tutorial closely. LCD screen was bought at a shop fully soldered.
Would truly appreciate any help!
Could it be an issue with the code? Here is the code:
// include the library code
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2); //LiquidCrystal lcd(RS, Enable, D4, D5, D6, D7)
// make some custom characters:
byte heart[8] = {0b00000, 0b01010, 0b11111, 0b11111, 0b11111, 0b01110, 0b00100, 0b00000};
byte smiley[8] = {0b00000, 0b00000, 0b01010, 0b00000, 0b00000, 0b10001, 0b01110, 0b00000};
byte frownie[8] = {0b00000, 0b00000, 0b01010, 0b00000, 0b00000, 0b00000, 0b01110, 0b10001};
byte armsDown[8] = {0b00100, 0b01010, 0b00100, 0b00100, 0b01110, 0b10101, 0b00100, 0b01010};
byte armsUp[8] = {0b00100, 0b01010, 0b00100, 0b10101, 0b01110, 0b00100, 0b00100, 0b01010};
void setup()
{
// set up the LCD's number of columns and rows:
lcd.begin(20, 4);
// create new characters
// support up to 8 characters of 5x8 pixels
// numbered as 0 to 7
lcd.createChar(0, heart);
lcd.createChar(1, smiley);
lcd.createChar(2, frownie);
lcd.createChar(3, armsDown);
lcd.createChar(4, armsUp);
// control contrast from Arduino PWM
// use Timer 1, PWM at pin 9 or 10
// connect LCD VO (pin 3) to Arduino pin 9
//TCCR1B = (TCCR1B & 0b11111000) | 0b001;
//analogWrite(9, 60);
}
void loop()
{
lcd.clear(); // clear screen
// lcd.rightToLeft(); // go right for the next letter
// lcd.leftToRight(); // go left for the next letter (default)
lcd.home(); // go to (0,0)
// set the cursor to (col,row)=(0,0), counting begins with 0
// lcd.setCursor(0, 0);
// print from 0 to 9:
for (int thisNum = 0; thisNum < 10; thisNum++)
{
lcd.print(thisNum);
delay(500);
}
// set the display to automatically scroll
lcd.autoscroll();
lcd.setCursor(20, 3); // set the cursor to (col,row)
// print from 0 to 9:
for (int thisNum = 0; thisNum < 10; thisNum++)
{
lcd.print(thisNum);
delay(500);
}
lcd.noAutoscroll(); // turn off automatic scrolling
lcd.clear();
lcd.setCursor(0, 0);
// Print a message to the LCD.
lcd.print("hello, world!");
for(int i=0; i<=4; i++)
{
lcd.scrollDisplayRight(); // scroll one position right
delay(200);
}
for(int i=0; i<=4; i++)
{
lcd.scrollDisplayLeft(); // scroll one position left
delay(200);
}
for(int i=10; i<=20; i++)
{
// if (i >= 15) lcd.blink(); // Turn on the blinking cursor
// if (i >= 15) lcd.cursor(); // Turn on the cursor
// if (i >= 15) lcd.noDisplay(); // Turn off the display
lcd.setCursor(16, 1);
lcd.print(i);
delay(300);
}
// lcd.noBlink(); // Turn off the blinking cursor
// lcd.noCursor(); // Turn off the cursor
// lcd.display(); // Turn on the display
// Print a number on the lcd
lcd.clear();
float number = 78.12345678;
lcd.setCursor(0, 0);
lcd.print("number = ");
lcd.print(number);
lcd.setCursor(0, 1);
lcd.print("no. = ");
lcd.print(number, 5);
lcd.setCursor(0, 2);
lcd.print("01234567890123456789");
lcd.setCursor(0, 3);
char str[] = "20 characters / line";
lcd.print(str);
delay(3000);
// Print a message on the lcd
lcd.clear();
lcd.setCursor(0, 1);
lcd.print("I ");
lcd.write((byte) 0); // when calling lcd.write(data), data must be cast as a byte
lcd.print(" BN2111 ");
lcd.write((byte) 1); // or byte(1)
lcd.print(" ! ");
lcd.write((byte) 2);
lcd.print(" ");
lcd.write((byte) 3);
lcd.print(" ");
lcd.write((byte) 4);
delay(3000);
}
If using a 10k potentiometer, connect both ends to ground.
