Improved library for Freetronics LCD shield

HelloWorld/HelloWorld.pde

@@ -0,0 +1,52 @@
+/*
+This example demonstrates how to use the FreetronicsLCD library, which extends the
+standard LiquidCrystal library to provide support for the Freetronics back light
+and Up/Down/Left/Right/Select buttons.  More information on the shield here:
+
+http://www.freetronics.com/pages/16x2-lcd-shield-quickstart-guide
+*/
+
+// include the library code:
+#include <FreetronicsLCD.h>
+
+// initialize the library
+FreetronicsLCD lcd;
+
+// Note: if you are using the USBDroid and have reassigned pin D9 on the LCD shield to some
+// other pin (e.g. A1), then you will need to initialize the shield with something like:
+// FreetronicsLCD lcd(A1);
+// See also: http://www.freetronics.com/pages/combining-the-lcd-keypad-shield-and-the-usbdroid
+
+void setup() {
+  // Enable the screen saver, which will automatically blank the screen after 10 seconds.
+  // The screen will wake up again when a button is pressed or lcd.display() is called.
+  lcd.enableScreenSaver();
+  
+  // Print a message to the LCD.
+  lcd.print("hello, world!");
+}
+
+void loop() {
+  // set the cursor to column 0, line 1
+  // (note: line 1 is the second row, since counting begins with 0):
+  lcd.setCursor(0, 1);
+  // print the number of seconds since reset:
+  lcd.print(millis()/1000);
+
+  // print the name of the button that is currently pressed  
+  lcd.setCursor(8, 1);
+  int button = lcd.getButton();
+  if (button == LCD_BUTTON_LEFT)
+    lcd.print("LEFT");
+  else if (button == LCD_BUTTON_RIGHT)
+    lcd.print("RIGHT");
+  else if (button == LCD_BUTTON_UP)
+    lcd.print("UP");
+  else if (button == LCD_BUTTON_DOWN)
+    lcd.print("DOWN");
+  else if (button == LCD_BUTTON_SELECT)
+    lcd.print("SELECT");
+  else if (button < 0) // button release
+    lcd.print("      ");
+}
+

libraries/FreetronicsLCD/FreetronicsLCD.cpp

@@ -0,0 +1,112 @@
+#include "FreetronicsLCD.h"
+#include <WProgram.h>
+
+#define LCD_BACK_LIGHT          3        // LCD backlight is on D3
+#define LCD_BUTTON_PIN          A0       // Button state is on A0
+
+#define LCD_BUTTON_VALUE_GAP    10
+#define LCD_BUTTON_RIGHT_VALUE  0
+#define LCD_BUTTON_UP_VALUE     145
+#define LCD_BUTTON_DOWN_VALUE   329
+#define LCD_BUTTON_LEFT_VALUE   505
+#define LCD_BUTTON_SELECT_VALUE 741
+
+void FreetronicsLCD::init()
+{
+    // The Freetronics display is 16x2.
+    begin(16, 2);
+
+    // Set the LCD back light to be initially on.
+    pinMode(LCD_BACK_LIGHT, OUTPUT);
+    digitalWrite(LCD_BACK_LIGHT, HIGH);
+
+    // Initialise button input.
+    pinMode(LCD_BUTTON_PIN, INPUT);
+    digitalWrite(LCD_BUTTON_PIN, LOW);
+    prevButton = LCD_BUTTON_NONE;
+    eatRelease = false;
+
+    // Initialize screen saver.
+    timeout = 0;
+    lastRestore = millis();
+    screenSaved = false;
+}
+
+void FreetronicsLCD::display()
+{
+    LiquidCrystal::display();
+    digitalWrite(LCD_BACK_LIGHT, HIGH);
+
+    screenSaved = false;
+    lastRestore = millis();
+}
+
+void FreetronicsLCD::noDisplay()
+{
+    LiquidCrystal::noDisplay();
+    digitalWrite(LCD_BACK_LIGHT, LOW);
+    screenSaved = true;
+}
+
+void FreetronicsLCD::enableScreenSaver(int timeoutSecs)
+{
+    if (timeoutSecs < 0)
+        timeout = 0;
+    else
+        timeout = ((unsigned long)timeoutSecs) * 1000;
+    display();
+}
+
+void FreetronicsLCD::disableScreenSaver()
+{
+    timeout = 0;
+    display();
+}
+
+int FreetronicsLCD::getButton()
+{
+    int value = analogRead(LCD_BUTTON_PIN);
+    int button;
+    if (value < (LCD_BUTTON_RIGHT_VALUE + LCD_BUTTON_VALUE_GAP))
+        button = LCD_BUTTON_RIGHT;
+    else if (value >= (LCD_BUTTON_UP_VALUE - LCD_BUTTON_VALUE_GAP) &&
+             value <= (LCD_BUTTON_UP_VALUE + LCD_BUTTON_VALUE_GAP))
+        button = LCD_BUTTON_UP;
+    else if (value >= (LCD_BUTTON_DOWN_VALUE - LCD_BUTTON_VALUE_GAP) &&
+             value <= (LCD_BUTTON_DOWN_VALUE + LCD_BUTTON_VALUE_GAP))
+        button = LCD_BUTTON_DOWN;
+    else if (value >= (LCD_BUTTON_LEFT_VALUE - LCD_BUTTON_VALUE_GAP) &&
+             value <= (LCD_BUTTON_LEFT_VALUE + LCD_BUTTON_VALUE_GAP))
+        button = LCD_BUTTON_LEFT;
+    else if (value >= (LCD_BUTTON_SELECT_VALUE - LCD_BUTTON_VALUE_GAP) &&
+             value <= (LCD_BUTTON_SELECT_VALUE + LCD_BUTTON_VALUE_GAP))
+        button = LCD_BUTTON_SELECT;
+    else
+        button = LCD_BUTTON_NONE;
+    if (prevButton == LCD_BUTTON_NONE && button != LCD_BUTTON_NONE) {
+        prevButton = button;
+        if (screenSaved) {
+            // Button pressed when screen saver active.
+            display();
+            eatRelease = true;
+            return LCD_BUTTON_NONE;
+        }
+        eatRelease = false;
+        lastRestore = millis();
+        return button;
+    } else if (prevButton != LCD_BUTTON_NONE && button == LCD_BUTTON_NONE) {
+        button = -prevButton;
+        prevButton = LCD_BUTTON_NONE;
+        lastRestore = millis();
+        if (eatRelease) {
+            eatRelease = false;
+            return LCD_BUTTON_NONE;
+        }
+        return button;
+    } else {
+        if (!screenSaved && prevButton == LCD_BUTTON_NONE &&
+                timeout != 0 && (millis() - lastRestore) >= timeout)
+            noDisplay();    // Activate screen saver.
+        return LCD_BUTTON_NONE;
+    }
+}

libraries/FreetronicsLCD/FreetronicsLCD.h

@@ -0,0 +1,69 @@
+#ifndef FreetronicsLCD_h
+#define FreetronicsLCD_h
+
+// Extended version of the LiquidCrystal library that works specifically
+// with Freetronics' 16x2 LCD display, including support for the back
+// light and the Up/Down/Left/Right/Select buttons.  More info:
+//
+// http://www.freetronics.com/pages/16x2-lcd-shield-quickstart-guide
+
+// Include a copy of the standard LiquidCrystal library so we can extend it.
+#include "utility/LiquidCrystal.h"
+
+// Button event codes.
+#define LCD_BUTTON_NONE             0
+#define LCD_BUTTON_LEFT             1
+#define LCD_BUTTON_RIGHT            2
+#define LCD_BUTTON_UP               3
+#define LCD_BUTTON_DOWN             4
+#define LCD_BUTTON_SELECT           5
+#define LCD_BUTTON_LEFT_RELEASED    -1
+#define LCD_BUTTON_RIGHT_RELEASED   -2
+#define LCD_BUTTON_UP_RELEASED      -3
+#define LCD_BUTTON_DOWN_RELEASED    -4
+#define LCD_BUTTON_SELECT_RELEASED  -5
+
+class FreetronicsLCD : public LiquidCrystal {
+public:
+    FreetronicsLCD() : LiquidCrystal(8, 9, 4, 5, 6, 7) { init(); }
+
+    // For USBDroid where D9 needs to be reassigned to some other pin.
+    FreetronicsLCD(uint8_t pin9) : LiquidCrystal(8, pin9, 4, 5, 6, 7) { init(); }
+
+    // Turn on the display, including the back light and the text.
+    // This will also reset the screen saver timeout.
+    void display();
+
+    // Turn off the display, including the back light and the text,
+    // effectively forcing the screen saver to activate immediately.
+    void noDisplay();
+
+    // Enable the screen saver and activate it after timeout seconds
+    // of inactivity on the buttons.  Note: the screen saver is activated
+    // during the call to getButton() so it must be polled regularly.
+    void enableScreenSaver(int timeoutSecs = 10);
+
+    // Disable the screen saver and turn the screen back on.
+    void disableScreenSaver();
+
+    // Determine if the screen saver is active.
+    bool isScreenSaved() const { return screenSaved; }
+
+    // Get the next button event, or LCD_BUTTON_NONE if no change
+    // since the last event.  If the screen saver is active, then
+    // pressing a button will disable the screen saver and return
+    // LCD_BUTTON_NONE as the button code.  Thus, any button can
+    // be used to wake up the screen.
+    int getButton();
+
+private:
+    int prevButton;
+    unsigned long timeout;
+    unsigned long lastRestore;
+    bool screenSaved;
+    bool eatRelease;
+
+    void init();
+};
+
+#endif

libraries/FreetronicsLCD/examples/HelloWorld/HelloWorld.pde

@@ -0,0 +1,52 @@
+/*
+This example demonstrates how to use the FreetronicsLCD library, which extends the
+standard LiquidCrystal library to provide support for the Freetronics back light
+and Up/Down/Left/Right/Select buttons.  More information on the shield here:
+
+http://www.freetronics.com/pages/16x2-lcd-shield-quickstart-guide
+*/
+
+// include the library code:
+#include <FreetronicsLCD.h>
+
+// initialize the library
+FreetronicsLCD lcd;
+
+// Note: if you are using the USBDroid and have reassigned pin D9 on the LCD shield to some
+// other pin (e.g. A1), then you will need to initialize the shield with something like:
+// FreetronicsLCD lcd(A1);
+// See also: http://www.freetronics.com/pages/combining-the-lcd-keypad-shield-and-the-usbdroid
+
+void setup() {
+  // Enable the screen saver, which will automatically blank the screen after 10 seconds.
+  // The screen will wake up again when a button is pressed or lcd.display() is called.
+  lcd.enableScreenSaver();
+  
+  // Print a message to the LCD.
+  lcd.print("hello, world!");
+}
+
+void loop() {
+  // set the cursor to column 0, line 1
+  // (note: line 1 is the second row, since counting begins with 0):
+  lcd.setCursor(0, 1);
+  // print the number of seconds since reset:
+  lcd.print(millis()/1000);
+
+  // print the name of the button that is currently pressed  
+  lcd.setCursor(8, 1);
+  int button = lcd.getButton();
+  if (button == LCD_BUTTON_LEFT)
+    lcd.print("LEFT");
+  else if (button == LCD_BUTTON_RIGHT)
+    lcd.print("RIGHT");
+  else if (button == LCD_BUTTON_UP)
+    lcd.print("UP");
+  else if (button == LCD_BUTTON_DOWN)
+    lcd.print("DOWN");
+  else if (button == LCD_BUTTON_SELECT)
+    lcd.print("SELECT");
+  else if (button < 0) // button release
+    lcd.print("      ");
+}
+

libraries/FreetronicsLCD/keywords.txt

@@ -0,0 +1,5 @@
+FreetronicsLCD	KEYWORD1
+getButton	KEYWORD2
+enableScreenSaver	KEYWORD2
+disableScreenSaver	KEYWORD2
+isScreenSaved	KEYWORD2

libraries/FreetronicsLCD/utility/LiquidCrystal.cpp

@@ -0,0 +1,309 @@
+#include "LiquidCrystal.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include "WProgram.h"
+
+// 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).
+
+LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
+			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
+			     uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
+{
+  init(0, rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7);
+}
+
+LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t enable,
+			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
+			     uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
+{
+  init(0, rs, 255, enable, d0, d1, d2, d3, d4, d5, d6, d7);
+}
+
+LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
+			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
+{
+  init(1, rs, rw, enable, d0, d1, d2, d3, 0, 0, 0, 0);
+}
+
+LiquidCrystal::LiquidCrystal(uint8_t rs,  uint8_t enable,
+			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
+{
+  init(1, rs, 255, enable, d0, d1, d2, d3, 0, 0, 0, 0);
+}
+
+void LiquidCrystal::init(uint8_t fourbitmode, uint8_t rs, uint8_t rw, uint8_t enable,
+			 uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
+			 uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
+{
+  _rs_pin = rs;
+  _rw_pin = rw;
+  _enable_pin = enable;
+  
+  _data_pins[0] = d0;
+  _data_pins[1] = d1;
+  _data_pins[2] = d2;
+  _data_pins[3] = d3; 
+  _data_pins[4] = d4;
+  _data_pins[5] = d5;
+  _data_pins[6] = d6;
+  _data_pins[7] = d7; 
+
+  pinMode(_rs_pin, OUTPUT);
+  // we can save 1 pin by not using RW. Indicate by passing 255 instead of pin#
+  if (_rw_pin != 255) { 
+    pinMode(_rw_pin, OUTPUT);
+  }
+  pinMode(_enable_pin, OUTPUT);
+  
+  if (fourbitmode)
+    _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
+  else 
+    _displayfunction = LCD_8BITMODE | LCD_1LINE | LCD_5x8DOTS;
+  
+  begin(16, 1);  
+}
+
+void LiquidCrystal::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
+  if (lines > 1) {
+    _displayfunction |= LCD_2LINE;
+  }
+  _numlines = lines;
+  _currline = 0;
+
+  // 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
+  delayMicroseconds(50000); 
+  // Now we pull both RS and R/W low to begin commands
+  digitalWrite(_rs_pin, LOW);
+  digitalWrite(_enable_pin, LOW);
+  if (_rw_pin != 255) { 
+    digitalWrite(_rw_pin, LOW);
+  }
+  
+  //put the LCD into 4 bit or 8 bit mode
+  if (! (_displayfunction & LCD_8BITMODE)) {
+    // 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);
+    delayMicroseconds(4500); // wait min 4.1ms
+
+    // second try
+    write4bits(0x03);
+    delayMicroseconds(4500); // wait min 4.1ms
+    
+    // third go!
+    write4bits(0x03); 
+    delayMicroseconds(150);
+
+    // finally, set to 4-bit interface
+    write4bits(0x02); 
+  } else {
+    // this is according to the hitachi HD44780 datasheet
+    // page 45 figure 23
+
+    // Send function set command sequence
+    command(LCD_FUNCTIONSET | _displayfunction);
+    delayMicroseconds(4500);  // wait more than 4.1ms
+
+    // second try
+    command(LCD_FUNCTIONSET | _displayfunction);
+    delayMicroseconds(150);
+
+    // third go
+    command(LCD_FUNCTIONSET | _displayfunction);
+  }
+
+  // finally, 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 romance languages)
+  _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
+  // set the entry mode
+  command(LCD_ENTRYMODESET | _displaymode);
+
+}
+
+/********** high level commands, for the user! */
+void LiquidCrystal::clear()
+{
+  command(LCD_CLEARDISPLAY);  // clear display, set cursor position to zero
+  delayMicroseconds(2000);  // this command takes a long time!
+}
+
+void LiquidCrystal::home()
+{
+  command(LCD_RETURNHOME);  // set cursor position to zero
+  delayMicroseconds(2000);  // this command takes a long time!
+}
+
+void LiquidCrystal::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::noDisplay() {
+  _displaycontrol &= ~LCD_DISPLAYON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+void LiquidCrystal::display() {
+  _displaycontrol |= LCD_DISPLAYON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+// Turns the underline cursor on/off
+void LiquidCrystal::noCursor() {
+  _displaycontrol &= ~LCD_CURSORON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+void LiquidCrystal::cursor() {
+  _displaycontrol |= LCD_CURSORON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+// Turn on and off the blinking cursor
+void LiquidCrystal::noBlink() {
+  _displaycontrol &= ~LCD_BLINKON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+void LiquidCrystal::blink() {
+  _displaycontrol |= LCD_BLINKON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+// These commands scroll the display without changing the RAM
+void LiquidCrystal::scrollDisplayLeft(void) {
+  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
+}
+void LiquidCrystal::scrollDisplayRight(void) {
+  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
+}
+
+// This is for text that flows Left to Right
+void LiquidCrystal::leftToRight(void) {
+  _displaymode |= LCD_ENTRYLEFT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// This is for text that flows Right to Left
+void LiquidCrystal::rightToLeft(void) {
+  _displaymode &= ~LCD_ENTRYLEFT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// This will 'right justify' text from the cursor
+void LiquidCrystal::autoscroll(void) {
+  _displaymode |= LCD_ENTRYSHIFTINCREMENT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// This will 'left justify' text from the cursor
+void LiquidCrystal::noAutoscroll(void) {
+  _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// Allows us to fill the first 8 CGRAM locations
+// with custom characters
+void LiquidCrystal::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]);
+  }
+}
+
+/*********** mid level commands, for sending data/cmds */
+
+inline void LiquidCrystal::command(uint8_t value) {
+  send(value, LOW);
+}
+
+inline void LiquidCrystal::write(uint8_t value) {
+  send(value, HIGH);
+}
+
+/************ low level data pushing commands **********/
+
+// write either command or data, with automatic 4/8-bit selection
+void LiquidCrystal::send(uint8_t value, uint8_t mode) {
+  digitalWrite(_rs_pin, mode);
+
+  // if there is a RW pin indicated, set it low to Write
+  if (_rw_pin != 255) { 
+    digitalWrite(_rw_pin, LOW);
+  }
+  
+  if (_displayfunction & LCD_8BITMODE) {
+    write8bits(value); 
+  } else {
+    write4bits(value>>4);
+    write4bits(value);
+  }
+}
+
+void LiquidCrystal::pulseEnable(void) {
+  digitalWrite(_enable_pin, LOW);
+  delayMicroseconds(1);    
+  digitalWrite(_enable_pin, HIGH);
+  delayMicroseconds(1);    // enable pulse must be >450ns
+  digitalWrite(_enable_pin, LOW);
+  delayMicroseconds(100);   // commands need > 37us to settle
+}
+
+void LiquidCrystal::write4bits(uint8_t value) {
+  for (int i = 0; i < 4; i++) {
+    pinMode(_data_pins[i], OUTPUT);
+    digitalWrite(_data_pins[i], (value >> i) & 0x01);
+  }
+
+  pulseEnable();
+}
+
+void LiquidCrystal::write8bits(uint8_t value) {
+  for (int i = 0; i < 8; i++) {
+    pinMode(_data_pins[i], OUTPUT);
+    digitalWrite(_data_pins[i], (value >> i) & 0x01);
+  }
+  
+  pulseEnable();
+}

libraries/FreetronicsLCD/utility/LiquidCrystal.h

@@ -0,0 +1,104 @@
+#ifndef LiquidCrystal_h
+#define LiquidCrystal_h
+
+#include <inttypes.h>
+#include "Print.h"
+
+// commands
+#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
+
+// flags for display entry mode
+#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
+
+class LiquidCrystal : public Print {
+public:
+  LiquidCrystal(uint8_t rs, uint8_t enable,
+		uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
+		uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
+  LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
+		uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
+		uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
+  LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
+		uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3);
+  LiquidCrystal(uint8_t rs, uint8_t enable,
+		uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3);
+
+  void init(uint8_t fourbitmode, uint8_t rs, uint8_t rw, uint8_t enable,
+	    uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
+	    uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
+    
+  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 leftToRight();
+  void rightToLeft();
+  void autoscroll();
+  void noAutoscroll();
+
+  void createChar(uint8_t, uint8_t[]);
+  void setCursor(uint8_t, uint8_t); 
+  virtual void write(uint8_t);
+  void command(uint8_t);
+private:
+  void send(uint8_t, uint8_t);
+  void write4bits(uint8_t);
+  void write8bits(uint8_t);
+  void pulseEnable();
+
+  uint8_t _rs_pin; // LOW: command.  HIGH: character.
+  uint8_t _rw_pin; // LOW: write to LCD.  HIGH: read from LCD.
+  uint8_t _enable_pin; // activated by a HIGH pulse.
+  uint8_t _data_pins[8];
+
+  uint8_t _displayfunction;
+  uint8_t _displaycontrol;
+  uint8_t _displaymode;
+
+  uint8_t _initialized;
+
+  uint8_t _numlines,_currline;
+};
+
+#endif