New version of LCD base class:

1) LCD and LCD_I2C now works together;
2) Added documentation in extras;
3) Moved defines in separate file;
4) Changed all examples to work with base class LCD;
5) Reworked virtual function send, write;
6) New initialization variants;
7) Added new files to gitignore
8) Added private functions for bit flags controlling in base LCD class;
9) Added destructor for all classes;
10) In base LCD class changed to protected: _cols, _rows, _displayfunction, _displaycontrol, _displaymode;
11) Added DEFAULT values as defines: LCD_DEFAULT_COLS,  LCD_DEFAULT_ROWS, LCD_DEFAULT_ADDR, LCD_BACKLIGHT;
12) Added variations of functiond to non _AVR_ boards;

.gitignore

@@ -1 +1,6 @@
 .vscode/settings.json
+.vscode
+
+.github/*
+.github
+.codespellrc

CMakeLists.txt

@@ -5,7 +5,7 @@
 cmake_minimum_required(VERSION 3.5)
 
 idf_component_register(SRCS "LiquidCrystal_Base.cpp" "LiquidCrystal.cpp" "LiquidCrystal_I2C.cpp"
-                       INCLUDE_DIRS "."
+                       INCLUDE_DIRS ".", "./coreLCD"
                        REQUIRES arduino)
 
-project(LiquidCrystal)
+project(LiquidCrystal_Base)

README.adoc

@@ -28,6 +28,8 @@ TIP: To find the latest versions, refer to https://github.com/VladVanyuk/BaseLiq
 
 * Added https://github.com/MartyMacGyver/Arduino_I2C_Scanner/tree/masterp[I2C_scanner] in examples
 
+* Added https://github.com/mrkaleArduinoLib/LiquidCrystal_I2C/tree/master[Complete Test] in examples. Also added readme file. 
+
 === License
 This project is released under a {License} License.
 

docs/extras/info/readme.txt

@@ -0,0 +1,47 @@
+// LiquidCrystal_I2C V2.0 - Mario H. [email protected]
+// Mods for Chinese I2C converter board - Murray R. Van Luyn. [email protected]
+
+The LiquidCrystal_I2C library is a modified version of the standard LiquidCrystal library as found on 
+the Arduino website.
+This library is intended to be used when a parallel HD44780 compatible LCD is controlled over I2C using 
+a Chinese PCF8574 extender.
+4 of the 8 outputs are used for LCD data lines 4 to 7.
+4 outputs are used for the Enable, register-select, Read/Write and backlight control lines.
+
+The Chinese PCF8574 extender is available in two versions, the PCF8574 and the PCF8574A.
+The only difference between the two is the I2C base address.
+The base address for the PCF8574 is 0x27 and the base address for the PCF8574A is 0x4E.
+The examples included in this zip file assume the use of an PCF8574 set for address 0x27 
+(A0, A1 and A3 un-linked, so pulled high).
+
+For PCF8574 the addressing is:
+
+Jp3	Jp2	Jp1		
+A2	A1	A0	Dec	Hex	
+L	L	L	32	0x20
+L	L	H	33	0x21
+L	H	L	34	0x22
+L	H	H	35	0x23
+H	L	L	36	0x24
+H	L	H	37	0x25
+H	H	L	38	0x26
+H	H	H	39	0x27
+
+For PCF8574A the addressing is:
+
+Jp3	Jp2	Jp1		
+A2	A1	A0	Dec	Hex	
+L	L	L	56	0x38
+L	L	H	57	0x39
+L	H	L	64	0x40
+L	H	H	74	0x4A
+H	L	L	75	0x4B
+H	L	H	76	0x4C
+H	H	L	77	0x4D
+H	H	H	78	0x4E
+
+For compatibility reasons this library contains some aliases for functions that are known under different 
+names in other libraries. This should make it fairly easy to implement the library in existing sketches 
+without changing to much code.
+Functions not supported by this library will return nothing at all and in case a return value is expected 
+the function will return 0.

examples/AllSymbols/AllSymbols.ino

@@ -1,5 +1,4 @@
-#include <Wire.h>
-#include <LiquidCrystal_I2C.h>
+#include <LiquidCrystal_Base.h>
 
 uint8_t bell[8] = {0x4, 0xe, 0xe, 0xe, 0x1f, 0x0, 0x4};
 uint8_t note[8] = {0x2, 0x3, 0x2, 0xe, 0x1e, 0xc, 0x0};
@@ -11,57 +10,57 @@ 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,
+{
+	0b00000,
+	0b10001,
+	0b00000,
+	0b00000,
+	0b10001,
+	0b01110,
+	0b00000,
+	0b00000
 };
 
 uint8_t wow[8] =
-	{
-		0b00000,
-		0b10001,
-		0b00000,
-		0b01110,
-		0b10001,
-		0b01110,
-		0b00000,
-		0b00000,
+{
+	0b00000,
+	0b10001,
+	0b00000,
+	0b01110,
+	0b10001,
+	0b01110,
+	0b00000,
+	0b00000
 };
 
 uint8_t anchor[8] =
-	{
-		0b01110,
-		0b01010,
-		0b01110,
-		0b00100,
-		0b10101,
-		0b10101,
-		0b01110,
-		0b00100};
+{
+	0b01110,
+	0b01010,
+	0b01110,
+	0b00100,
+	0b10101,
+	0b10101,
+	0b01110,
+	0b00100
+};
 
 uint8_t snow[8] =
-	{
-		0b01000,
-		0b11101,
-		0b01011,
-		0b00001,
-		0b00100,
-		0b01110,
-		0b00100,
-		0b10000};
+{
+	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();
@@ -94,14 +93,27 @@ void keyCodes2004(uint8_t i)
 	lcd.print("Codes 0x");
 	lcd.print(i, HEX);
 	lcd.print("-0x");
-	lcd.print(i + 16, HEX);
+	lcd.print(i + 60, HEX);
 	lcd.setCursor(0, 1);
 
-	for (int j = 0; j < 16; j++)
+	for (int j = 0; j < 20; j++)
+	{
+		lcd.write(i + j);
+	}
+
+	i+=20;
+	lcd.setCursor(0, 2);
+	for (int j = 0; j < 20; j++)
+	{
+		lcd.write(i + j);
+	}
+
+	i+=20;
+	lcd.setCursor(0, 3);
+	for (int j = 0; j < 20; j++)
 	{
 		lcd.write(i + j);
 	}
-
 }
 
 void keyCodes1602(uint8_t i)
@@ -117,22 +129,21 @@ void keyCodes1602(uint8_t i)
 	{
 		lcd2.write(i + j);
 	}
-
 }
 
 // display all keycodes
 void displayKeyCodes(void)
 {
+  // symbols 0x10-0x20 are usualy shown as empty 
 	uint8_t i = 0;
-
 	while (1)
 	{
 
 		keyCodes2004(i);
 		keyCodes1602(i);
-		delay(5000);
+		delay(10000);
 
-    i += 16;
+		i += 16;
 	}
 }
 

examples/Autoscroll/Autoscroll.ino

@@ -31,7 +31,7 @@
  by Tom Igoe
  modified 7 Nov 2016
  by Arturo Guadalupi
- modified 30 Nov 2024
+ modified 2 Feb 2024
  by Vladislav Vanyuk
 
  This example code is in the public domain.
@@ -40,29 +40,27 @@
  https://github.com/arduino-libraries/LiquidCrystal
 */
 
+
+// choose what connection type your display is
 // #define TYPE_LCD
 #define TYPE_LCD_I2C
+
+// include the library code:
 #include <LiquidCrystal_Base.h>
 
+// virtual base class pointer to an object 
 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_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)
-
+LiquidCrystal_I2C lcd_i2c(0x27, 16, 2) //(0x27, 20, 4)
 #endif
 
-
-
 void setup() {
   Serial.begin(9600);
 

examples/Blink/Blink.ino

@@ -31,6 +31,8 @@
  by Tom Igoe
  modified 7 Nov 2016
  by Arturo Guadalupi
+ modified 2 Feb 2024
+ by Vladislav Vanyuk
 
  This example code is in the public domain.
 
@@ -40,25 +42,41 @@
 */
 
 // include the library code:
-#include <LiquidCrystal.h>
+#include <LiquidCrystal_Base.h>
 
+#define LCD_TYPE 1 // 0 - LCD, 1 - LCD_I2C
+
+LiquidCrystal_Base *lcd;
+
+#if (LCD_TYPE == 0)
 // 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 (LCD_TYPE == 1)
+LiquidCrystal_I2C lcd_i2c(0x27, 16, 2); //(0x27, 20, 4)
+#else
+error("Please select the LCD type")
+#endif
 
 void setup() {
+#if (LCD_TYPE == 0)
+  lcd = &lcd_normal;
+#elif (LCD_TYPE == 1)
+  lcd = &lcd_i2c;
+#endif
+
   // set up the LCD's number of columns and rows:
-  lcd.begin(16, 2);
-  // Print a message to the LCD.
-  lcd.print("hello, world!");
+  lcd->begin(16, 2);
+  // Print a message to the LCD
+  lcd->print("Cursor Blinking");
 }
 
 void loop() {
   // Turn off the blinking cursor:
-  lcd.noBlink();
+  lcd->noBlink();
   delay(3000);
   // Turn on the blinking cursor:
-  lcd.blink();
+  lcd->blink();
   delay(3000);
 }