Added (fixed) Liquid_Crystal_I2C class;

In LiquidCrystal_Base class changed <begin> function. Now virtual function <send> is used instead of <write4bits> to initialize HD44780;
Changed <send> function: now parameter mode is used to indicate if object is in INIT_MODE or inited and sending COMMAND/DATA;
Functions like: begin and init are now virtual;
Removed from classes <_initialized> flag;
Updated all examples with extention <.pde> to <.ino>;
Added defines for default values of columns, lines, i2c address;
Parameters: _cols, _rows, _addr now have default values;
Added new begin function with parameters like in standart LiquidCrystal class, so LiquidCrystal_I2C class objects now can have same initialization as standart Arduino library;
Added setCursor function in LiquidCrystal_Base class;
In LiquidCrystal_Base class functions: begin(uint8_t cols, uint8_t rows...), write4bits, send are now pure virtual;
Added (fixed) example <AllSymbols.ino>: showcase of all symbols in lcd memory;
Changed example <Autoscroll.ino> to work with both current types of lcd objects (normal, i2c). Base class object pointer is used.
For now all functions are public for developing purpose. In next version functions for sending information, initializing will become private/protected;
For now only avr  architecture is supported and tested;

.gitignore

@@ -0,0 +1 @@
+.vscode/settings.json

examples/AllSymbols/AllSymbols.ino

@@ -0,0 +1,142 @@
+#include <Wire.h>
+#include <LiquidCrystal_I2C.h>
+
+uint8_t bell[8] = {0x4, 0xe, 0xe, 0xe, 0x1f, 0x0, 0x4};
+uint8_t note[8] = {0x2, 0x3, 0x2, 0xe, 0x1e, 0xc, 0x0};
+uint8_t clock[8] = {0x0, 0xe, 0x15, 0x17, 0x11, 0xe, 0x0};
+uint8_t heart[8] = {0x0, 0xa, 0x1f, 0x1f, 0xe, 0x4, 0x0};
+uint8_t duck[8] = {0x0, 0xc, 0x1d, 0xf, 0xf, 0x6, 0x0};
+uint8_t check[8] = {0x0, 0x1, 0x3, 0x16, 0x1c, 0x8, 0x0};
+uint8_t cross[8] = {0x0, 0x1b, 0xe, 0x4, 0xe, 0x1b, 0x0};
+uint8_t retarrow[8] = {0x1, 0x1, 0x5, 0x9, 0x1f, 0x8, 0x4};
+
+uint8_t happy[8] =
+	{
+		0b00000,
+		0b10001,
+		0b00000,
+		0b00000,
+		0b10001,
+		0b01110,
+		0b00000,
+		0b00000,
+};
+
+uint8_t wow[8] =
+	{
+		0b00000,
+		0b10001,
+		0b00000,
+		0b01110,
+		0b10001,
+		0b01110,
+		0b00000,
+		0b00000,
+};
+
+uint8_t anchor[8] =
+	{
+		0b01110,
+		0b01010,
+		0b01110,
+		0b00100,
+		0b10101,
+		0b10101,
+		0b01110,
+		0b00100};
+
+uint8_t snow[8] =
+	{
+		0b01000,
+		0b11101,
+		0b01011,
+		0b00001,
+		0b00100,
+		0b01110,
+		0b00100,
+		0b10000};
+
+// Set the LCD address to 0x27 for a 16 chars and 2 line display
+LiquidCrystal_I2C lcd(0x27, 20, 4);
+LiquidCrystal_I2C lcd2(0x26, 16, 2);
+
+LiquidCrystal_I2C *lcd_ptr;
+
+void setup()
+{
+	lcd.init();
+	lcd2.init();
+
+	lcd.createChar(0, bell);
+	lcd.createChar(1, note);
+	lcd.createChar(2, clock);
+	lcd.createChar(3, heart);
+	lcd.createChar(4, duck);
+	lcd.createChar(5, check);
+	lcd.createChar(6, cross);
+	lcd.createChar(7, retarrow);
+
+	lcd2.createChar(0, happy);
+	lcd2.createChar(1, wow);
+	lcd2.createChar(2, anchor);
+	lcd2.createChar(3, snow);
+
+	lcd.print("LCD Memory");
+	lcd2.print("LCD Memory");
+
+	delay(5000);
+	displayKeyCodes();
+}
+
+void keyCodes2004(uint8_t i)
+{
+	lcd.clear();
+	lcd.print("Codes 0x");
+	lcd.print(i, HEX);
+	lcd.print("-0x");
+	lcd.print(i + 16, HEX);
+	lcd.setCursor(0, 1);
+
+	for (int j = 0; j < 16; j++)
+	{
+		lcd.write(i + j);
+	}
+
+}
+
+void keyCodes1602(uint8_t i)
+{
+	lcd2.clear();
+	lcd2.print("Codes 0x");
+	lcd2.print(i, HEX);
+	lcd2.print("-0x");
+	lcd2.print(i + 16, HEX);
+	lcd2.setCursor(0, 1);
+
+	for (int j = 0; j < 16; j++)
+	{
+		lcd2.write(i + j);
+	}
+
+}
+
+// display all keycodes
+void displayKeyCodes(void)
+{
+	uint8_t i = 0;
+
+	while (1)
+	{
+
+		keyCodes2004(i);
+		keyCodes1602(i);
+		delay(5000);
+
+    i += 16;
+	}
+}
+
+void loop()
+{
+	displayKeyCodes();
+}

examples/Autoscroll/Autoscroll.ino

@@ -31,47 +31,73 @@
  by Tom Igoe
  modified 7 Nov 2016
  by Arturo Guadalupi
+ modified 30 Nov 2024
+ by Vladislav Vanyuk
 
  This example code is in the public domain.
 
  https://docs.arduino.cc/learn/electronics/lcd-displays#autoscroll-example
  https://github.com/arduino-libraries/LiquidCrystal
 */
 
+// #define TYPE_LCD
+#define TYPE_LCD_I2C
+#include <LiquidCrystal_Base.h>
+
+LiquidCrystal_Base *lcd;
+
+#if (defined TYPE_LCD)
 // 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);
+LiquidCrystal lcd_normal(rs, en, d4, d5, d6, d7);
+
+#elif (defined TYPE_LCD_I2C)
+
+#include <LiquidCrystal_I2C.h>
+LiquidCrystal_I2C lcd_i2c(0x27, 20, 4); //(0x27, 16, 2)
+
+#endif
+
+
 
 void setup() {
-  // set up the LCD's number of columns and rows:
-  lcd.begin(16, 2);
+  Serial.begin(9600);
+
+#ifdef TYPE_LCD
+  lcd = &lcd_normal;
+  Serial.println("normal");
+#elif defined (TYPE_LCD_I2C)
+  lcd = &lcd_i2c;
+  Serial.println("i2c");
+#endif
+  lcd->begin(20, 4);
+  lcd->clear();
 }
 
 void loop() {
   // set the cursor to (0,0):
-  lcd.setCursor(0, 0);
+  lcd->setCursor(0, 0);
   // print from 0 to 9:
   for (int thisChar = 0; thisChar < 10; thisChar++) {
-    lcd.print(thisChar);
+    lcd->print(thisChar);
     delay(500);
   }
 
   // set the cursor to (16,1):
-  lcd.setCursor(16, 1);
+  lcd->setCursor(16, 1);
   // set the display to automatically scroll:
-  lcd.autoscroll();
+  lcd->autoscroll();
   // print from 0 to 9:
   for (int thisChar = 0; thisChar < 10; thisChar++) {
-    lcd.print(thisChar);
+    lcd->print(thisChar);
     delay(500);
   }
   // turn off automatic scrolling
-  lcd.noAutoscroll();
+  lcd->noAutoscroll();
 
   // clear screen for the next loop:
-  lcd.clear();
+  lcd->clear();
 }

library.properties

@@ -1,9 +1,9 @@
 name=LiquidCrystal
-version=1.1.0
+version=1.1.1
 author=Arduino, Adafruit
 maintainer=VladVanyuk <vladvanyuk@gmail.com>
 sentence=Allows you to create general LCD object and use same methods in derived (LCDs) classes.
 paragraph=Virtual base class abstraction allows you to use one library for LiquidCrystal and LiquidCrystal_I2C (LCDs).
 category=Display
 url=https://github.com/VladVanyuk/LiquidCrystal
-architectures=*
+architectures=avr