LiquidCrystal_I2C SparkCore

LiquidCrystal_I2C.cpp

// LiquidCrystal_I2C V2.0
 
// When the display powers up, it is configured as follows:
//
// 1. Display clear
// 2. Function set:
//    DL = 1; 8-bit interface data
//    N = 0; 1-line display
//    F = 0; 5x8 dot character font
// 3. Display on/off control:
//    D = 0; Display off
//    C = 0; Cursor off
//    B = 0; Blinking off
// 4. Entry mode set:
//    I/D = 1; Increment by 1
//    S = 0; No shift
//
// Note, however, that resetting the Arduino doesn't reset the LCD, so we
// can't assume that its in that state when a sketch starts (and the
// LiquidCrystal constructor is called).

#include "application.h"
#include "LiquidCrystal_I2C.h"

 
LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr,uint8_t lcd_cols,uint8_t lcd_rows)
{
  _Addr = lcd_Addr;
  _cols = lcd_cols;
  _rows = lcd_rows;
  _backlightval = LCD_NOBACKLIGHT;
}
 
void LiquidCrystal_I2C::init(){
        init_priv();
}
 
void LiquidCrystal_I2C::init_priv()
{
        Wire.begin();
        _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
        begin(_cols, _rows);  
}
 
void LiquidCrystal_I2C::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
        if (lines > 1) {
                _displayfunction |= LCD_2LINE;
        }
        _numlines = lines;
 
        // for some 1 line displays you can select a 10 pixel high font
        if ((dotsize != 0) && (lines == 1)) {
                _displayfunction |= LCD_5x10DOTS;
        }
 
        // 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 50
        delay(50);
 
        // Now we pull both RS and R/W low to begin commands
        expanderWrite(_backlightval);   // reset expanderand turn backlight off (Bit 8 =1)
        delay(1000);
 
        //put the LCD into 4 bit mode
        // this is according to the hitachi HD44780 datasheet
        // figure 24, pg 46
       
          // we start in 8bit mode, try to set 4 bit mode
   write4bits(0x03 << 4);
   delayMicroseconds(4500); // wait min 4.1ms
   
   // second try
   write4bits(0x03 << 4);
   delayMicroseconds(4500); // wait min 4.1ms
   
   // third go!
   write4bits(0x03 << 4);
   delayMicroseconds(150);
   
   // finally, set to 4-bit interface
   write4bits(0x02 << 4);
 
 
 
        // set # lines, font size, etc.
        command(LCD_FUNCTIONSET | _displayfunction);  
       
        // turn the display on with no cursor or blinking default
        _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
        display();
       
        // clear it off
        clear();
       
        // Initialize to default text direction (for roman languages)
        _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
       
        // set the entry mode
        command(LCD_ENTRYMODESET | _displaymode);
       
        home();
 
}
 
 
 
/********** high level commands, for the user! */
void LiquidCrystal_I2C::clear(){
        command(LCD_CLEARDISPLAY);// clear display, set cursor position to zero
        delayMicroseconds(2000);  // this command takes a long time!
}
 
void LiquidCrystal_I2C::home(){
        command(LCD_RETURNHOME);  // set cursor position to zero
        delayMicroseconds(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 ) {
                row = _numlines-1;    // we count rows starting w/0
        }
        command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
}
 
// Turn the display on/off (quickly)
void LiquidCrystal_I2C::noDisplay() {
        _displaycontrol &= ~LCD_DISPLAYON;
        command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_I2C::display() {
        _displaycontrol |= LCD_DISPLAYON;
        command(LCD_DISPLAYCONTROL | _displaycontrol);
}
 
// Turns the underline cursor on/off
void LiquidCrystal_I2C::noCursor() {
        _displaycontrol &= ~LCD_CURSORON;
        command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_I2C::cursor() {
        _displaycontrol |= LCD_CURSORON;
        command(LCD_DISPLAYCONTROL | _displaycontrol);
}
 
// Turn on and off the blinking cursor
void LiquidCrystal_I2C::noBlink() {
        _displaycontrol &= ~LCD_BLINKON;
        command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_I2C::blink() {
        _displaycontrol |= LCD_BLINKON;
        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::scrollDisplayRight(void) {
        command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}
 
// This is for text that flows Left to Right
void LiquidCrystal_I2C::leftToRight(void) {
        _displaymode |= LCD_ENTRYLEFT;
        command(LCD_ENTRYMODESET | _displaymode);
}
 
// This is for text that flows Right to Left
void LiquidCrystal_I2C::rightToLeft(void) {
        _displaymode &= ~LCD_ENTRYLEFT;
        command(LCD_ENTRYMODESET | _displaymode);
}
 
// This will 'right justify' text from the cursor
void LiquidCrystal_I2C::autoscroll(void) {
        _displaymode |= LCD_ENTRYSHIFTINCREMENT;
        command(LCD_ENTRYMODESET | _displaymode);
}
 
// This will 'left justify' text from the cursor
void LiquidCrystal_I2C::noAutoscroll(void) {
        _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
        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[]) {
        location &= 0x7; // we only have 8 locations 0-7
        command(LCD_SETCGRAMADDR | (location << 3));
        for (int i=0; i<8; i++) {
                write(charmap[i]);
        }
}
 
// Turn the (optional) backlight off/on
void LiquidCrystal_I2C::noBacklight(void) {
        _backlightval=LCD_NOBACKLIGHT;
        expanderWrite(0);
}
 
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);
}
 
inline size_t LiquidCrystal_I2C::write(uint8_t value) {
        send(value, 1);
        return 0;
}
 
 
 
 
 
/************ low level data pushing commands **********/
 
// write either command or data
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) {
        expanderWrite(value);
        pulseEnable(value);
}
 
void LiquidCrystal_I2C::expanderWrite(uint8_t _data){                                        
        Wire.beginTransmission(_Addr);
        Wire.write((int)(_data) | _backlightval);
        Wire.endTransmission();  
        }
 
void LiquidCrystal_I2C::pulseEnable(uint8_t _data){
        expanderWrite(_data | (1<<2));  // En high
        delayMicroseconds(1);           // enable pulse must be >450ns
       
        expanderWrite(_data & ~(1<<2)); // En low
        delayMicroseconds(50);          // commands need > 37us to settle
}
 
 
// Alias functions
 
void LiquidCrystal_I2C::cursor_on(){
        cursor();
}
 
void LiquidCrystal_I2C::cursor_off(){
        noCursor();
}
 
void LiquidCrystal_I2C::blink_on(){
        blink();
}
 
void LiquidCrystal_I2C::blink_off(){
        noBlink();
}
 
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){
        if(new_val){
                backlight();            // turn backlight on
        }else{
                noBacklight();          // turn backlight off
        }
}
 
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
        print(c);
}
 
 
// unsupported API functions
void LiquidCrystal_I2C::off(){}
void LiquidCrystal_I2C::on(){}
void LiquidCrystal_I2C::setDelay (int cmdDelay,int charDelay) {}
uint8_t LiquidCrystal_I2C::status(){return 0;}
uint8_t LiquidCrystal_I2C::keypad (){return 0;}
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){}
void LiquidCrystal_I2C::draw_vertical_graph(uint8_t row, uint8_t column, uint8_t len,  uint8_t pixel_row_end){}
void LiquidCrystal_I2C::setContrast(uint8_t new_val){}

LiquidCrystal_I2C.h

#define ARDUINO_H

#ifndef LiquidCrystal_I2C_h
#define LiquidCrystal_I2C_h
 
#define LCD_CLEARDISPLAY 0x01
#define LCD_RETURNHOME 0x02
#define LCD_ENTRYMODESET 0x04
#define LCD_DISPLAYCONTROL 0x08
#define LCD_CURSORSHIFT 0x10
#define LCD_FUNCTIONSET 0x20
#define LCD_SETCGRAMADDR 0x40
#define LCD_SETDDRAMADDR 0x80
 
#define LCD_ENTRYRIGHT 0x00
#define LCD_ENTRYLEFT 0x02
#define LCD_ENTRYSHIFTINCREMENT 0x01
#define LCD_ENTRYSHIFTDECREMENT 0x00
 
// flags for display on/off control
#define LCD_DISPLAYON 0x04
#define LCD_DISPLAYOFF 0x00
#define LCD_CURSORON 0x02
#define LCD_CURSOROFF 0x00
#define LCD_BLINKON 0x01
#define LCD_BLINKOFF 0x00
 
// flags for display/cursor shift
#define LCD_DISPLAYMOVE 0x08
#define LCD_CURSORMOVE 0x00
#define LCD_MOVERIGHT 0x04
#define LCD_MOVELEFT 0x00
 
// flags for function set
#define LCD_8BITMODE 0x10
#define LCD_4BITMODE 0x00
#define LCD_2LINE 0x08
#define LCD_1LINE 0x00
#define LCD_5x10DOTS 0x04
#define LCD_5x8DOTS 0x00
 
// flags for backlight control
#define LCD_BACKLIGHT 0x08
#define LCD_NOBACKLIGHT 0x00
 
//#define En B00000100  // Enable bit
//#define Rw B00000010  // Read/Write bit
//#define Rs B00000001  // Register select bit
 
class LiquidCrystal_I2C : public Print {
public:
  LiquidCrystal_I2C(uint8_t lcd_Addr,uint8_t lcd_cols,uint8_t lcd_rows);
  void begin(uint8_t cols, uint8_t rows, uint8_t charsize = LCD_5x8DOTS );
  void clear();
  void home();
  void noDisplay();
  void display();
  void noBlink();
  void blink();
  void noCursor();
  void cursor();
  void scrollDisplayLeft();
  void scrollDisplayRight();
  void printLeft();
  void printRight();
  void leftToRight();
  void rightToLeft();
  void shiftIncrement();
  void shiftDecrement();
  void noBacklight();
  void backlight();
  void autoscroll();
  void noAutoscroll();
  void createChar(uint8_t, uint8_t[]);
  void setCursor(uint8_t, uint8_t);
  virtual size_t write(uint8_t); //changed to size_t
  void command(uint8_t);
  void init();
 
////compatibility API function aliases
void blink_on();            // alias for blink()
void blink_off();                 // alias for noBlink()
void cursor_on();                 // alias for cursor()
void cursor_off();                // alias for noCursor()
void setBacklight(uint8_t new_val);       // alias for backlight() and nobacklight()
void load_custom_character(uint8_t char_num, uint8_t *rows);  // alias for createChar()
void printstr(const char[]);
 
////Unsupported API functions (not implemented in this library)
uint8_t status();
void setContrast(uint8_t new_val);
uint8_t keypad();
void setDelay(int,int);
void on();
void off();
uint8_t init_bargraph(uint8_t graphtype);
void draw_horizontal_graph(uint8_t row, uint8_t column, uint8_t len,  uint8_t pixel_col_end);
void draw_vertical_graph(uint8_t row, uint8_t column, uint8_t len,  uint8_t pixel_col_end);
   
 
private:
  void init_priv();
  void send(uint8_t, uint8_t);
  void write4bits(uint8_t);
  void expanderWrite(uint8_t);
  void pulseEnable(uint8_t);
  uint8_t _Addr;
  uint8_t _displayfunction;
  uint8_t _displaycontrol;
  uint8_t _displaymode;
  uint8_t _numlines;
  uint8_t _cols;
  uint8_t _rows;
  uint8_t _backlightval;
};
 
#endif

LiquidCrystal_I2C_example.ino

#include "application.h"
#include "LiquidCrystal_I2C.h"

LiquidCrystal_I2C   *lcd;

void setup()
{
    lcd = new LiquidCrystal_I2C(0x27, 16, 2);  // set the LCD address to 0x20 for a 16x2 //SparkCore bug, address is actually 27 but shifted (0x27*2)
    lcd->init();                      // initialize the lcd
    lcd->backlight();
    lcd->clear();
    lcd->setCursor(0,0);
    lcd->print("---Spark*Core---");
    lcd->setCursor(0,1);
    lcd->print("Uptime:");
}
 
void loop()
{
    lcd->setCursor(7,1);
    lcd->print((int)(millis()/1000));
    delay(200);
}

Possible origin of this code may be found here
http://hmario.home.xs4all.nl/arduino/LiquidCrystal_I2C/