Valentino Saitz / Mbed 2 deprecated LiquidCrystal_I2C

Port of the Arduino library with the same library. Includes a instance of the Print library from arduino

Dependencies:   mbed Print

Summary

A Conversion of the Arduino LiquidCrystal_I2C by Frank de Brabander to MBED
Version of original Library: 1.1.2
Information from the original library: The library allows to control I2C displays with functions extremely similar to LiquidCrystal library.
Original Github: https://github.com/johnrickman/LiquidCrystal_I2C

Code Example

This is a working example using the basic library features

example.cpp

#include "LiquidCrystal_I2C.h"

LiquidCrystal_I2C lcd(0x27, 20, 4, I2C_SDA, I2C_SCL);
void setup();
void loop();

//Arduino style setup function
void setup() {
	lcd.init();
	for (int i = 0; i < 3; i++) {
		lcd.backlight();
		wait_ms(250);
		lcd.noBacklight();
		wait_ms(250);
	}
	lcd.backlight();
	lcd.setCursor(3, 0); // Start at character 4 on line 0
	lcd.print("Hello, world!");
	wait_ms(500);
	lcd.setCursor(2, 1);
	lcd.print("From YourDuino");
	wait_ms(500);
	lcd.setCursor(0, 2);
	lcd.print("20 by 4 Line Display");
	lcd.setCursor(1, 3);
	wait_ms(1000);
	lcd.print("DVSProductions.de");
	wait_ms(8000);
}

//print some random characters
void loop() {
	//lcd.setCursor(rand() % 20, rand() % 4);
	//lcd.print(rand() % 10);      
	for (int x = 0; x != 20; x++)
		for (int y = 0; y != 20; y++)
			lcd.print(rand() % 10);
}

//Behave like an Arduino
int main() {
	setup();
	while (true)loop();
}

Misc

It is important to note that the library requires the init function to be called before sending any data. Instead of the arduino typical:

arduino.ino

LiquidCrystal_I2C lcd(0x27, 20, 4);
void setup(){
	lcd.begin(20, 4);
}

We pass the pins and size to the constructor and then just call the init function:

mbed.cpp

LiquidCrystal_I2C lcd(0x27, 20, 4, I2C_SDA, I2C_SCL);
void setup(){
	lcd.init();
}

Also important is that the begin function still has value. It is now able to change the size of the LCD after the constructor. This might have few applications, but it is more powerful than the Arduino version, where the parameters had barely any use.

Files at this revision

API Documentation at this revision

Revision 4:402a5c6b2457, committed 2019-08-15

Comitter:
DVSProductions
Date:
Thu Aug 15 13:55:21 2019 +0000
Parent:
3:9c8694d5744a
Commit message:
INSANE PERFORMANCE BOOST

Changed in this revision

LiquidCrystal_I2C.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
diff -r 9c8694d5744a -r 402a5c6b2457 LiquidCrystal_I2C.cpp
--- a/LiquidCrystal_I2C.cpp	Mon Jul 29 04:41:55 2019 +0000
+++ b/LiquidCrystal_I2C.cpp	Thu Aug 15 13:55:21 2019 +0000
@@ -1,13 +1,18 @@
 // Based on the work by DFRobot upgraded by DVSProductions
 #include "LiquidCrystal_I2C.h"
 #include <inttypes.h>
+/*********** mid level commands, for sending data/cmds */
+#define COMMAND(value) send(value, 0)
 #define printIIC(args) i2c->write(_Addr, args, 1)
-size_t LiquidCrystal_I2C::write(uint8_t value)
-{
+size_t LiquidCrystal_I2C::write(uint8_t value) {
     send(value, Rs);
     return 1;
 }
 
+inline void LiquidCrystal_I2C::command(uint8_t value) {
+    send(value, 0);
+}
+
 // When the display powers up, it is configured as follows:
 //
 // 1. Display clear
@@ -30,29 +35,24 @@
 /*!
 Creates a new LCD instance
 !*/
-LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t lcd_cols,
-                                     uint8_t lcd_rows, PinName sda,
-                                     PinName scl)
-{
+LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t lcd_cols, uint8_t lcd_rows, PinName sda, PinName scl) {
     _Addr = lcd_Addr << 1;
     _cols = lcd_cols;
     _rows = lcd_rows;
     _backlightval = LCD_NOBACKLIGHT;
     i2c = new I2C(sda, scl);
+    i2c->frequency(1000000);
 }
 
-void LiquidCrystal_I2C::init()
-{
+ void LiquidCrystal_I2C::init() {
     init_priv();
 }
 
-void LiquidCrystal_I2C::init_priv()
-{
+ void LiquidCrystal_I2C::init_priv() {
     _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
     begin_priv();
 }
-void LiquidCrystal_I2C::begin_priv(uint8_t dotsize)
-{
+void LiquidCrystal_I2C::begin_priv(uint8_t dotsize) {
     if (_rows > 1) {
         _displayfunction |= LCD_2LINE;
     }
@@ -63,7 +63,7 @@
     }
     // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
     // according to datasheet, we need at least 40ms after power rises above 2.7V
-    // before sending commands. Arduino can turn on way befer 4.5V so we'll wait
+    // before sending commands. Nucleo can turn on way befer 4.5V so we'll wait
     // 50
     wait_ms(50);
     // Now we pull both RS and R/W low to begin commands
@@ -85,7 +85,7 @@
     // finally, set to 4-bit interface
     write4bits(0x02 << 4);
     // set # lines, font size, etc.
-    command(LCD_FUNCTIONSET | _displayfunction);
+    COMMAND(LCD_FUNCTIONSET | _displayfunction);
     // turn the display on with no cursor or blinking default
     _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
     display();
@@ -94,237 +94,202 @@
     // Initialize to default text direction (for roman languages)
     _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
     // set the entry mode
-    command(LCD_ENTRYMODESET | _displaymode);
+    COMMAND(LCD_ENTRYMODESET | LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT);
     home();
 }
-void LiquidCrystal_I2C::begin(uint8_t cols, uint8_t lines, uint8_t dotsize)
-{
-    _cols=cols;
-    _rows=lines;
+void LiquidCrystal_I2C::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
+    _cols = cols;
+    _rows = lines;
     begin_priv();
 }
 
 /********** high level commands, for the user! */
-void LiquidCrystal_I2C::clear()
-{
-    command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero
+void LiquidCrystal_I2C::clear() {
+    COMMAND(LCD_CLEARDISPLAY); // clear display, set cursor position to zero
     wait_us(2000);             // this command takes a long time!
 }
 
-void LiquidCrystal_I2C::home()
-{
-    command(LCD_RETURNHOME); // set cursor position to zero
+void LiquidCrystal_I2C::home() {
+    COMMAND(LCD_RETURNHOME); // set cursor position to zero
     wait_us(2000);           // this command takes a long time!
 }
 
-void LiquidCrystal_I2C::setCursor(uint8_t col, uint8_t row)
-{
-    int row_offsets[] = {0x00, 0x40, 0x14, 0x54};
-    if (row > _numlines) {
+void LiquidCrystal_I2C::setCursor(uint8_t col, uint8_t row) {
+    int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
+    if (row > _numlines)
         row = _numlines - 1; // we count rows starting w/0
-    }
-    command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
+    COMMAND(LCD_SETDDRAMADDR | (col + row_offsets[row]));
 }
 
 // Turn the display on/off (quickly)
-void LiquidCrystal_I2C::noDisplay()
-{
+void LiquidCrystal_I2C::noDisplay() {
     _displaycontrol &= ~LCD_DISPLAYON;
-    command(LCD_DISPLAYCONTROL | _displaycontrol);
+    COMMAND(LCD_DISPLAYCONTROL | _displaycontrol);
 }
-void LiquidCrystal_I2C::display()
-{
+void LiquidCrystal_I2C::display() {
     _displaycontrol |= LCD_DISPLAYON;
-    command(LCD_DISPLAYCONTROL | _displaycontrol);
+    COMMAND(LCD_DISPLAYCONTROL | _displaycontrol);
 }
 
 // Turns the underline cursor on/off
-void LiquidCrystal_I2C::noCursor()
-{
+void LiquidCrystal_I2C::noCursor() {
     _displaycontrol &= ~LCD_CURSORON;
-    command(LCD_DISPLAYCONTROL | _displaycontrol);
+    COMMAND(LCD_DISPLAYCONTROL | _displaycontrol);
 }
-void LiquidCrystal_I2C::cursor()
-{
+void LiquidCrystal_I2C::cursor() {
     _displaycontrol |= LCD_CURSORON;
-    command(LCD_DISPLAYCONTROL | _displaycontrol);
+    COMMAND(LCD_DISPLAYCONTROL | _displaycontrol);
 }
 
 // Turn on and off the blinking cursor
-void LiquidCrystal_I2C::noBlink()
-{
+void LiquidCrystal_I2C::noBlink() {
     _displaycontrol &= ~LCD_BLINKON;
-    command(LCD_DISPLAYCONTROL | _displaycontrol);
+    COMMAND(LCD_DISPLAYCONTROL | _displaycontrol);
 }
-void LiquidCrystal_I2C::blink()
-{
+void LiquidCrystal_I2C::blink() {
     _displaycontrol |= LCD_BLINKON;
-    command(LCD_DISPLAYCONTROL | _displaycontrol);
+    COMMAND(LCD_DISPLAYCONTROL | _displaycontrol);
 }
 
 // These commands scroll the display without changing the RAM
-void LiquidCrystal_I2C::scrollDisplayLeft(void)
-{
-    command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
+void LiquidCrystal_I2C::scrollDisplayLeft(void) {
+    COMMAND(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
 }
-void LiquidCrystal_I2C::scrollDisplayRight(void)
-{
-    command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
+void LiquidCrystal_I2C::scrollDisplayRight(void) {
+    COMMAND(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
 }
 
 // This is for text that flows Left to Right
-void LiquidCrystal_I2C::leftToRight(void)
-{
+void LiquidCrystal_I2C::leftToRight(void) {
     _displaymode |= LCD_ENTRYLEFT;
-    command(LCD_ENTRYMODESET | _displaymode);
+    COMMAND(LCD_ENTRYMODESET | _displaymode);
 }
 
 // This is for text that flows Right to Left
-void LiquidCrystal_I2C::rightToLeft(void)
-{
+void LiquidCrystal_I2C::rightToLeft(void) {
     _displaymode &= ~LCD_ENTRYLEFT;
-    command(LCD_ENTRYMODESET | _displaymode);
+    COMMAND(LCD_ENTRYMODESET | _displaymode);
 }
 
 // This will 'right justify' text from the cursor
-void LiquidCrystal_I2C::autoscroll(void)
-{
+void LiquidCrystal_I2C::autoscroll(void) {
     _displaymode |= LCD_ENTRYSHIFTINCREMENT;
-    command(LCD_ENTRYMODESET | _displaymode);
+    COMMAND(LCD_ENTRYMODESET | _displaymode);
 }
 
 // This will 'left justify' text from the cursor
-void LiquidCrystal_I2C::noAutoscroll(void)
-{
+void LiquidCrystal_I2C::noAutoscroll(void) {
     _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
-    command(LCD_ENTRYMODESET | _displaymode);
+    COMMAND(LCD_ENTRYMODESET | _displaymode);
 }
 
 // Allows us to fill the first 8 CGRAM locations
 // with custom characters
-void LiquidCrystal_I2C::createChar(uint8_t location, uint8_t charmap[])
-{
+void LiquidCrystal_I2C::createChar(uint8_t location, uint8_t charmap[]) {
     location &= 0x7; // we only have 8 locations 0-7
-    command(LCD_SETCGRAMADDR | (location << 3));
-    for (int i = 0; i < 8; i++) {
+    COMMAND(LCD_SETCGRAMADDR | (location << 3));
+    for (uint8_t i = 0; i != 8; i++)
         write(charmap[i]);
-    }
 }
 
 // Turn the (optional) backlight off/on
-void LiquidCrystal_I2C::noBacklight(void)
-{
+void LiquidCrystal_I2C::noBacklight(void) {
     _backlightval = LCD_NOBACKLIGHT;
     expanderWrite(0);
 }
 
-void LiquidCrystal_I2C::backlight(void)
-{
+void LiquidCrystal_I2C::backlight(void) {
     _backlightval = LCD_BACKLIGHT;
     expanderWrite(0);
 }
 
-/*********** mid level commands, for sending data/cmds */
-
-inline void LiquidCrystal_I2C::command(uint8_t value)
-{
-    send(value, 0);
-}
-
 /************ low level data pushing commands **********/
 
 // write either command or data
-void LiquidCrystal_I2C::send(uint8_t value, uint8_t mode)
-{
+void LiquidCrystal_I2C::send(uint8_t value, uint8_t mode) {
     uint8_t highnib = value & 0xf0;
     uint8_t lownib = (value << 4) & 0xf0;
     write4bits((highnib) | mode);
     write4bits((lownib) | mode);
 }
 
-void LiquidCrystal_I2C::write4bits(uint8_t value)
-{
+void LiquidCrystal_I2C::write4bits(uint8_t value) {
     expanderWrite(value);
     pulseEnable(value);
 }
 char buff;
-void LiquidCrystal_I2C::expanderWrite(uint8_t _data)
-{
+inline void LiquidCrystal_I2C::expanderWrite(uint8_t _data) {
     buff = (_data) | _backlightval;
     printIIC(&buff);
 }
 
-void LiquidCrystal_I2C::pulseEnable(uint8_t _data)
-{
+void LiquidCrystal_I2C::pulseEnable(uint8_t _data) {
     expanderWrite(_data | En); // En high
     wait_us(1);                // enable pulse must be >450ns
 
     expanderWrite(_data & ~En); // En low
-    wait_us(45);                // commands need > 37us to settle
+    wait_us(10);                // commands need > 37us to settle
 }
 
 // Alias functions
 
-void LiquidCrystal_I2C::cursor_on()
-{
+inline void LiquidCrystal_I2C::cursor_on() {
     cursor();
 }
 
-void LiquidCrystal_I2C::cursor_off()
-{
+inline void LiquidCrystal_I2C::cursor_off() {
     noCursor();
 }
 
-void LiquidCrystal_I2C::blink_on()
-{
+inline void LiquidCrystal_I2C::blink_on() {
     blink();
 }
 
-void LiquidCrystal_I2C::blink_off()
-{
+inline void LiquidCrystal_I2C::blink_off() {
     noBlink();
 }
 
-void LiquidCrystal_I2C::load_custom_character(uint8_t char_num, uint8_t *rows)
-{
+inline void LiquidCrystal_I2C::load_custom_character(uint8_t char_num, uint8_t *rows) {
     createChar(char_num, rows);
 }
 
-void LiquidCrystal_I2C::setBacklight(uint8_t new_val)
-{
+void LiquidCrystal_I2C::setBacklight(uint8_t new_val) {
     if (new_val)
         backlight(); // turn backlight on
     else
         noBacklight(); // turn backlight off
 }
 
-void LiquidCrystal_I2C::printstr(const char c[])
-{
+void LiquidCrystal_I2C::printstr(const char c[]) {
     // This function is not identical to the function used for "real" I2C displays
-    // it's here so the user sketch doesn't have to be changed
+    // it's here so the use sketch doesn't have to be changed
     print(c);
 }
 
 // unsupported API functions
-void LiquidCrystal_I2C::off() {}
-void LiquidCrystal_I2C::on() {}
+void LiquidCrystal_I2C::off() {
+    noBacklight();
+}
+void LiquidCrystal_I2C::on() {
+    begin_priv();
+    backlight();
+}
 void LiquidCrystal_I2C::setDelay(int cmdDelay, int charDelay) {}
-uint8_t LiquidCrystal_I2C::status()
-{
+uint8_t LiquidCrystal_I2C::status() {
     return 0;
 }
-uint8_t LiquidCrystal_I2C::keypad()
-{
+uint8_t LiquidCrystal_I2C::keypad() {
     return 0;
 }
-uint8_t LiquidCrystal_I2C::init_bargraph(uint8_t graphtype)
-{
+uint8_t LiquidCrystal_I2C::init_bargraph(uint8_t graphtype) {
     return 0;
 }
 void LiquidCrystal_I2C::draw_horizontal_graph(uint8_t row, uint8_t column,
-        uint8_t len,
-        uint8_t pixel_col_end) {}
+    uint8_t len,
+    uint8_t pixel_col_end) {
+}
 void LiquidCrystal_I2C::draw_vertical_graph(uint8_t row, uint8_t column,
-        uint8_t len,
-        uint8_t pixel_row_end) {}
+    uint8_t len,
+    uint8_t pixel_row_end) {
+}
 void LiquidCrystal_I2C::setContrast(uint8_t new_val) {}

diff -r 9c8694d5744a -r 402a5c6b2457 mbed.bld
--- a/mbed.bld	Mon Jul 29 04:41:55 2019 +0000
+++ b/mbed.bld	Thu Aug 15 13:55:21 2019 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/ad3be0349dc5
\ No newline at end of file
+https://os.mbed.com/users/mbed_official/code/mbed/builds/65be27845400
\ No newline at end of file