Hello World for SparkCore Arduino firmware and AdaFruit 16x2 OLED display

HelloSparkCore.cpp

// Uses an Adafruit OLED on pins D0 - D6 for output, see http://www.adafruit.com/products/823

/* LCD RS pin to digital pin 0
 * LCD R/W pin to digital pin 1
 * LCD Enable pin to digital pin 2
 * LCD D4 pin to digital pin 3
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 5
 * LCD D7 pin to digital pin 6
*/

// Adafruit OLED library: https://github.com/ladyada/Adafruit_CharacterOLED
// Derived from LiquidCrystal by David Mellis
// With portions adapted from Elco Jacobs OLEDFourBit
// Modified for 4-bit operation of the Winstar 16x2 Character OLED
// By W. Earl for Adafruit - 6/30/12
#include <stdio.h>
#include <string.h>
#include <inttypes.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 0x28
#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_JAPANESE    0x00
#define LCD_EUROPEAN_I  0x01
#define LCD_RUSSIAN     0x02
#define LCD_EUROPEAN_II 0x03


class Adafruit_CharacterOLED : public Print {
public:
  Adafruit_CharacterOLED(uint8_t rs, uint8_t rw, uint8_t enable,
		uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
  
  void init(uint8_t rs, uint8_t rw, uint8_t enable,
	    uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
    
  void begin(uint8_t cols, uint8_t rows);

  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 size_t write(uint8_t);
  void command(uint8_t);
  
private:
  void send(uint8_t, uint8_t);
  void write4bits(uint8_t);
  void pulseEnable();
  void waitForReady();

  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 _busy_pin;   // HIGH means not ready for next command
  uint8_t _data_pins[4];

  uint8_t _displayfunction;
  uint8_t _displaycontrol;
  uint8_t _displaymode;
  uint8_t _initialized;
  uint8_t _currline;
  uint8_t _numlines;
};

// On power up, the display is initilaized as:
// 1. Display clear
// 2. Function set:
//    DL="1": 8-bit interface data
//    N="0": 1-line display
//    F="0": 5 x 8 dot character font
// 3. Power turn off
//    PWR=”0”
// 4. Display on/off control: D="0": Display off C="0": Cursor off B="0": Blinking off
// 5. Entry mode set
//    I/D="1": Increment by 1
//    S="0": No shift
// 6. Cursor/Display shift/Mode / Pwr
//    S/C=”0”, R/L=”1”: Shifts cursor position to the right
//    G/C=”0”: Character mode
//    Pwr=”1”: Internal DCDC power on
//
// 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).

Adafruit_CharacterOLED::Adafruit_CharacterOLED(uint8_t rs, uint8_t rw, uint8_t enable,
			     uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
{
  init(rs, rw, enable, d4, d5, d6, d7);
}

void Adafruit_CharacterOLED::init(uint8_t rs, uint8_t rw, uint8_t enable,
			 uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
{
  _rs_pin = rs;
  _rw_pin = rw;
  _enable_pin = enable;
  
  _data_pins[0] = d4;
  _data_pins[1] = d5;
  _data_pins[2] = d6;
  _data_pins[3] = _busy_pin = d7;

  pinMode(_rs_pin, OUTPUT);
  pinMode(_rw_pin, OUTPUT);
  pinMode(_enable_pin, OUTPUT);
  
  _displayfunction = LCD_FUNCTIONSET | LCD_4BITMODE;
   
  begin(16, 2);  
}

void Adafruit_CharacterOLED::begin(uint8_t cols, uint8_t lines) 
{
  _numlines = lines;
  _currline = 0;
  
  pinMode(_rs_pin, OUTPUT);
  pinMode(_rw_pin, OUTPUT);
  pinMode(_enable_pin, OUTPUT);
  
  digitalWrite(_rs_pin, LOW);
  digitalWrite(_enable_pin, LOW);
  digitalWrite(_rw_pin, LOW);
  
  delayMicroseconds(50000); // give it some time to power up
  
  // Now we pull both RS and R/W low to begin commands
  
  for (int i = 0; i < 4; i++) {
    pinMode(_data_pins[i], OUTPUT);
    digitalWrite(_data_pins[i], LOW);
  }

  // Initialization sequence is not quite as documented by Winstar.
  // Documented sequence only works on initial power-up.  An additional
  // step is required to handle a warm-restart.
  //
  // In the data sheet, the timing specs are all zeros(!).  These have been tested to 
  // reliably handle both warm & cold starts
  //

  write4bits(0x03);  // Missing step from doc. Thanks to Elco Jacobs
  delayMicroseconds(5000);
  write4bits(0x02);
  delayMicroseconds(5000);
  write4bits(0x02);
  delayMicroseconds(5000);
  write4bits(0x08);
   
  delayMicroseconds(5000);
  
  command(0x08);	// Turn Off
  delayMicroseconds(5000);
  command(0x01);	// Clear Display
  delayMicroseconds(5000);
  command(0x06);	// Set Entry Mode
  delayMicroseconds(5000);
  command(0x02);	// Home Cursor
  delayMicroseconds(5000);
  command(0x0C);	// Turn On - enable cursor & blink
  delayMicroseconds(5000);
}

/********** high level commands, for the user! */
void Adafruit_CharacterOLED::clear()
{
  command(LCD_CLEARDISPLAY);  // clear display, set cursor position to zero
  //  delayMicroseconds(2000);  // this command takes a long time!
}

void Adafruit_CharacterOLED::home()
{
  command(LCD_RETURNHOME);  // set cursor position to zero
  //  delayMicroseconds(2000);  // this command takes a long time!
}

void Adafruit_CharacterOLED::setCursor(uint8_t col, uint8_t row)
{
  uint8_t row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
  if ( row >= _numlines ) 
  {
    row = 0;  //write to first line if out off bounds
  }
  
  command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
}

// Turn the display on/off (quickly)
void Adafruit_CharacterOLED::noDisplay() 
{
  _displaycontrol &= ~LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void Adafruit_CharacterOLED::display() 
{
  _displaycontrol |= LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turns the underline cursor on/off
void Adafruit_CharacterOLED::noCursor() 
{
  _displaycontrol &= ~LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void Adafruit_CharacterOLED::cursor() 
{
  _displaycontrol |= LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turn on and off the blinking cursor
void Adafruit_CharacterOLED::noBlink() 
{
  _displaycontrol &= ~LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void Adafruit_CharacterOLED::blink() 
{
  _displaycontrol |= LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// These commands scroll the display without changing the RAM
void Adafruit_CharacterOLED::scrollDisplayLeft(void) 
{
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}
void Adafruit_CharacterOLED::scrollDisplayRight(void) 
{
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}

// This is for text that flows Left to Right
void Adafruit_CharacterOLED::leftToRight(void) 
{
  _displaymode |= LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This is for text that flows Right to Left
void Adafruit_CharacterOLED::rightToLeft(void) 
{
  _displaymode &= ~LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'right justify' text from the cursor
void Adafruit_CharacterOLED::autoscroll(void) 
{
  _displaymode |= LCD_ENTRYSHIFTINCREMENT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'left justify' text from the cursor
void Adafruit_CharacterOLED::noAutoscroll(void) 
{
  _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// Allows us to fill the first 8 CGRAM locations
// with custom characters
void Adafruit_CharacterOLED::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 Adafruit_CharacterOLED::command(uint8_t value) 
{
  send(value, LOW);
  waitForReady();
}

inline size_t Adafruit_CharacterOLED::write(uint8_t value) 
{
  send(value, HIGH);
  waitForReady();
  return 0;
}

/************ low level data pushing commands **********/

// write either command or data
void Adafruit_CharacterOLED::send(uint8_t value, uint8_t mode) 
{
  digitalWrite(_rs_pin, mode);
  pinMode(_rw_pin, OUTPUT);
  digitalWrite(_rw_pin, LOW);
  
  write4bits(value>>4);
  write4bits(value);
}

void Adafruit_CharacterOLED::pulseEnable(void) 
{
  digitalWrite(_enable_pin, HIGH);
  delayMicroseconds(50);    // Timing Spec?
  digitalWrite(_enable_pin, LOW);
}

void Adafruit_CharacterOLED::write4bits(uint8_t value) 
{
  for (int i = 0; i < 4; i++) 
  {
    pinMode(_data_pins[i], OUTPUT);
    digitalWrite(_data_pins[i], (value >> i) & 0x01);
  }
  delayMicroseconds(50); // Timing spec?
  pulseEnable();
}

// Poll the busy bit until it goes LOW
void Adafruit_CharacterOLED::waitForReady(void) 
{
  unsigned char busy = 1;
  pinMode(_busy_pin, INPUT);
  digitalWrite(_rs_pin, LOW);	
  digitalWrite(_rw_pin, HIGH);      
  do
  {
  	digitalWrite(_enable_pin, LOW);
  	digitalWrite(_enable_pin, HIGH);

  	delayMicroseconds(10);
  	busy = digitalRead(_busy_pin);
  	digitalWrite(_enable_pin, LOW);
  	
  	pulseEnable();		// get remaining 4 bits, which are not used.
  }
  while(busy);
  
  pinMode(_busy_pin, OUTPUT);
  digitalWrite(_rw_pin, LOW);
}

Adafruit_CharacterOLED *lcd;

void setup() {
    lcd = new Adafruit_CharacterOLED(D0, D1, D2, D3, D4, D5, D6);
    lcd->setCursor(5,0);
    lcd->print("Hello");
    lcd->setCursor(3,1);
    lcd->print("SparkCore!");
}

void loop() {
}