Adafruit_SSD1306.cpp

00001 /*********************************************************************
00002 This is a library for our Monochrome OLEDs based on SSD1306 drivers
00003 
00004   Pick one up today in the adafruit shop!
00005   ------> http://www.adafruit.com/category/63_98
00006 
00007 These displays use SPI to communicate, 4 or 5 pins are required to
00008 interface
00009 
00010 Adafruit invests time and resources providing this open source code,
00011 please support Adafruit and open-source hardware by purchasing
00012 products from Adafruit!
00013 
00014 Written by Limor Fried/Ladyada  for Adafruit Industries.
00015 BSD license, check license.txt for more information
00016 All text above, and the splash screen below must be included in any redistribution
00017 *********************************************************************/
00018 
00019 /*
00020  *  Modified by Neal Horman 7/14/2012 for use in mbed
00021  *  Modified by JojoS 03/07/2015
00022  *   add flipVertical option to constructor
00023  *   add use of 'rst' is optional, maybe NC in constructor
00024  *   add command SSD1306_SETPAGESTARTADDRESS to reset page start address (important when no hardware reset is uesed)
00025  */
00026 
00027 #include "mbed.h"
00028 #include "Adafruit_SSD1306.h"
00029 
00030 #define SSD1306_SETCONTRAST 0x81
00031 #define SSD1306_DISPLAYALLON_RESUME 0xA4
00032 #define SSD1306_DISPLAYALLON 0xA5
00033 #define SSD1306_NORMALDISPLAY 0xA6
00034 #define SSD1306_INVERTDISPLAY 0xA7
00035 #define SSD1306_DISPLAYOFF 0xAE
00036 #define SSD1306_DISPLAYON 0xAF
00037 #define SSD1306_SETDISPLAYOFFSET 0xD3
00038 #define SSD1306_SETCOMPINS 0xDA
00039 #define SSD1306_SETVCOMDETECT 0xDB
00040 #define SSD1306_SETDISPLAYCLOCKDIV 0xD5
00041 #define SSD1306_SETPRECHARGE 0xD9
00042 #define SSD1306_SETMULTIPLEX 0xA8
00043 #define SSD1306_SETLOWCOLUMN 0x00
00044 #define SSD1306_SETHIGHCOLUMN 0x10
00045 #define SSD1306_SETSTARTLINE 0x40
00046 #define SSD1306_MEMORYMODE 0x20
00047 #define SSD1306_COMSCANINC 0xC0
00048 #define SSD1306_COMSCANDEC 0xC8
00049 #define SSD1306_SEGREMAP 0xA0
00050 #define SSD1306_CHARGEPUMP 0x8D
00051 #define SSD1306_SETPAGESTARTADDRESS 0xB0
00052 
00053 Adafruit_SSD1306::Adafruit_SSD1306(PinName reset, uint8_t rawHeight, uint8_t rawWidth, bool flipVertical)
00054     : Adafruit_GFX(rawWidth,rawHeight)
00055     , _reset(reset,false)
00056     , _flipVertical(flipVertical)
00057 {
00058     buffer.resize(rawHeight * rawWidth / 8);
00059 }
00060 
00061 void Adafruit_SSD1306::begin(uint8_t vccstate)
00062 {
00063     if (_reset.is_connected()) {        // reset input is not present on every SSD1306 display board, so usage is optional
00064         _reset = 1;
00065         // VDD (3.3V) goes high at start, lets just chill for a ms
00066         wait_ms(1);
00067         // bring reset low
00068         _reset = 0;
00069         // wait 10ms
00070         wait_ms(10);
00071         // bring out of reset
00072         _reset = 1;
00073         // turn on VCC (9V?)
00074     }
00075 
00076 
00077     command(SSD1306_DISPLAYOFF);
00078     command(SSD1306_SETDISPLAYCLOCKDIV);
00079     command(0x80);                                  // the suggested ratio 0x80
00080 
00081     command(SSD1306_SETMULTIPLEX);
00082     command(_rawHeight-1);
00083 
00084     command(SSD1306_SETDISPLAYOFFSET);
00085     command(0x0);                                   // no offset
00086 
00087     command(SSD1306_SETSTARTLINE | 0x0);            // line #0
00088 
00089     command(SSD1306_CHARGEPUMP);
00090     command((vccstate == SSD1306_EXTERNALVCC) ? 0x10 : 0x14);
00091 
00092     command(SSD1306_MEMORYMODE);
00093     command(0x00);                                  // 0x0 act like ks0108
00094 
00095 
00096     if (_flipVertical) {
00097         command(SSD1306_SEGREMAP | 0x0);
00098         command(SSD1306_COMSCANINC);
00099     } else {
00100         command(SSD1306_SEGREMAP | 0x1);
00101         command(SSD1306_COMSCANDEC);                    // flip vertically
00102     }
00103 
00104 
00105     command(SSD1306_SETLOWCOLUMN | 0x0);  // low col = 0
00106     command(SSD1306_SETHIGHCOLUMN | 0x0);  // hi col = 0
00107     command(SSD1306_SETSTARTLINE | 0x0); // line #0
00108     command(SSD1306_SETPAGESTARTADDRESS | 0x0);
00109 
00110     command(SSD1306_SETCOMPINS);
00111     command(_rawHeight == 32 ? 0x02 : 0x12);        // TODO - calculate based on _rawHieght ?
00112 
00113     command(SSD1306_SETCONTRAST);
00114     command(_rawHeight == 32 ? 0x8F : ((vccstate == SSD1306_EXTERNALVCC) ? 0x9F : 0xCF) );
00115 
00116     command(SSD1306_SETPRECHARGE);
00117     command((vccstate == SSD1306_EXTERNALVCC) ? 0x22 : 0xF1);
00118 
00119     command(SSD1306_SETVCOMDETECT);
00120     command(0x40);
00121 
00122     command(SSD1306_DISPLAYALLON_RESUME);
00123 
00124     command(SSD1306_NORMALDISPLAY);
00125 
00126     command(SSD1306_DISPLAYON);
00127 }
00128 
00129 // Set a single pixel
00130 void Adafruit_SSD1306::drawPixel(int16_t x, int16_t y, uint16_t color)
00131 {
00132     if ((x < 0) || (x >= width()) || (y < 0) || (y >= height()))
00133         return;
00134 
00135     // check rotation, move pixel around if necessary
00136     switch (getRotation()) {
00137         case 1:
00138             swap(x, y);
00139             x = _rawWidth - x - 1;
00140             break;
00141         case 2:
00142             x = _rawWidth - x - 1;
00143             y = _rawHeight - y - 1;
00144             break;
00145         case 3:
00146             swap(x, y);
00147             y = _rawHeight - y - 1;
00148             break;
00149     }
00150 
00151     // x is which column
00152     if (color == WHITE)
00153         buffer[x+ (y/8)*_rawWidth] |= _BV((y%8));
00154     else // else black
00155         buffer[x+ (y/8)*_rawWidth] &= ~_BV((y%8));
00156 }
00157 
00158 void Adafruit_SSD1306::invertDisplay(bool i)
00159 {
00160     command(i ? SSD1306_INVERTDISPLAY : SSD1306_NORMALDISPLAY);
00161 }
00162 
00163 void Adafruit_SSD1306::flipVertical(bool flip)
00164 {
00165     _flipVertical = flip;
00166 
00167     if (_flipVertical) {
00168         command(SSD1306_SEGREMAP | 0x0);
00169         command(SSD1306_COMSCANINC);
00170     } else {
00171         command(SSD1306_SEGREMAP | 0x1);
00172         command(SSD1306_COMSCANDEC);                    // flip vertically
00173     }
00174 }
00175 
00176 // Send the display buffer out to the display
00177 void Adafruit_SSD1306::display(void)
00178 {
00179     command(SSD1306_SETLOWCOLUMN | 0x0);  // low col = 0
00180     command(SSD1306_SETHIGHCOLUMN | 0x0);  // hi col = 0
00181     command(SSD1306_SETSTARTLINE | 0x0); // line #0
00182     sendDisplayBuffer();
00183 }
00184 
00185 // Clear the display buffer. Requires a display() call at some point afterwards
00186 void Adafruit_SSD1306::clearDisplay(void)
00187 {
00188     std::fill(buffer.begin(),buffer.end(),0);
00189 }
00190 
00191 void Adafruit_SSD1306::splash(void)
00192 {
00193 #ifndef NO_SPLASH_ADAFRUIT
00194     const uint8_t adaFruitLogo[64 * 128 / 8] = {
00195         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00196         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00197         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00198         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80,
00199         0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00200         0x00, 0x80, 0x80, 0xC0, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00201         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00202         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00203         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00204         0x00, 0x00, 0x00, 0x00, 0x80, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC, 0xF8, 0xE0, 0x00, 0x00, 0x00, 0x00,
00205         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80,
00206         0x80, 0x80, 0x00, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80, 0x80, 0x80, 0x00, 0xFF,
00207         0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80, 0x80, 0x00, 0x00, 0x80, 0x80, 0x00, 0x00,
00208         0x80, 0xFF, 0xFF, 0x80, 0x80, 0x00, 0x80, 0x80, 0x00, 0x80, 0x80, 0x80, 0x80, 0x00, 0x80, 0x80,
00209         0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x00, 0x00, 0x8C, 0x8E, 0x84, 0x00, 0x00, 0x80, 0xF8,
00210         0xF8, 0xF8, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00211         0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xE0, 0xE0, 0xC0, 0x80,
00212         0x00, 0xE0, 0xFC, 0xFE, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00,
00213         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0xFF, 0xC7, 0x01, 0x01,
00214         0x01, 0x01, 0x83, 0xFF, 0xFF, 0x00, 0x00, 0x7C, 0xFE, 0xC7, 0x01, 0x01, 0x01, 0x01, 0x83, 0xFF,
00215         0xFF, 0xFF, 0x00, 0x38, 0xFE, 0xC7, 0x83, 0x01, 0x01, 0x01, 0x83, 0xC7, 0xFF, 0xFF, 0x00, 0x00,
00216         0x01, 0xFF, 0xFF, 0x01, 0x01, 0x00, 0xFF, 0xFF, 0x07, 0x01, 0x01, 0x01, 0x00, 0x00, 0x7F, 0xFF,
00217         0x80, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x7F, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x01, 0xFF,
00218         0xFF, 0xFF, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00219         0x03, 0x0F, 0x3F, 0x7F, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xE7, 0xC7, 0xC7, 0x8F,
00220         0x8F, 0x9F, 0xBF, 0xFF, 0xFF, 0xC3, 0xC0, 0xF0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, 0xFC, 0xFC,
00221         0xFC, 0xFC, 0xFC, 0xFC, 0xFC, 0xF8, 0xF8, 0xF0, 0xF0, 0xE0, 0xC0, 0x00, 0x01, 0x03, 0x03, 0x03,
00222         0x03, 0x03, 0x01, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03, 0x03, 0x03, 0x03, 0x01, 0x01,
00223         0x03, 0x01, 0x00, 0x00, 0x00, 0x01, 0x03, 0x03, 0x03, 0x03, 0x01, 0x01, 0x03, 0x03, 0x00, 0x00,
00224         0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
00225         0x03, 0x03, 0x03, 0x03, 0x03, 0x01, 0x00, 0x00, 0x00, 0x01, 0x03, 0x01, 0x00, 0x00, 0x00, 0x03,
00226         0x03, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00227         // 128x32^^^  128x64vvv
00228         0x00, 0x00, 0x00, 0x80, 0xC0, 0xE0, 0xF0, 0xF9, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x3F, 0x1F, 0x0F,
00229         0x87, 0xC7, 0xF7, 0xFF, 0xFF, 0x1F, 0x1F, 0x3D, 0xFC, 0xF8, 0xF8, 0xF8, 0xF8, 0x7C, 0x7D, 0xFF,
00230         0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0x3F, 0x0F, 0x07, 0x00, 0x30, 0x30, 0x00, 0x00,
00231         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00232         0x00, 0x00, 0x00, 0x00, 0xFE, 0xFE, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00233         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xE0, 0xC0, 0x00,
00234         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x30, 0x00, 0x00, 0x00, 0x00,
00235         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00236         0x00, 0xC0, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0x7F, 0x3F, 0x1F,
00237         0x0F, 0x07, 0x1F, 0x7F, 0xFF, 0xFF, 0xF8, 0xF8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xF8, 0xE0,
00238         0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0xFE, 0x00, 0x00,
00239         0x00, 0xFC, 0xFE, 0xFC, 0x0C, 0x06, 0x06, 0x0E, 0xFC, 0xF8, 0x00, 0x00, 0xF0, 0xF8, 0x1C, 0x0E,
00240         0x06, 0x06, 0x06, 0x0C, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0xFE, 0xFE, 0x00, 0x00, 0x00, 0x00, 0xFC,
00241         0xFE, 0xFC, 0x00, 0x18, 0x3C, 0x7E, 0x66, 0xE6, 0xCE, 0x84, 0x00, 0x00, 0x06, 0xFF, 0xFF, 0x06,
00242         0x06, 0xFC, 0xFE, 0xFC, 0x0C, 0x06, 0x06, 0x06, 0x00, 0x00, 0xFE, 0xFE, 0x00, 0x00, 0xC0, 0xF8,
00243         0xFC, 0x4E, 0x46, 0x46, 0x46, 0x4E, 0x7C, 0x78, 0x40, 0x18, 0x3C, 0x76, 0xE6, 0xCE, 0xCC, 0x80,
00244         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00245         0x00, 0x00, 0x00, 0x00, 0x01, 0x07, 0x0F, 0x1F, 0x1F, 0x3F, 0x3F, 0x3F, 0x3F, 0x1F, 0x0F, 0x03,
00246         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0F, 0x0F, 0x00, 0x00,
00247         0x00, 0x0F, 0x0F, 0x0F, 0x00, 0x00, 0x00, 0x00, 0x0F, 0x0F, 0x00, 0x00, 0x03, 0x07, 0x0E, 0x0C,
00248         0x18, 0x18, 0x0C, 0x06, 0x0F, 0x0F, 0x0F, 0x00, 0x00, 0x01, 0x0F, 0x0E, 0x0C, 0x18, 0x0C, 0x0F,
00249         0x07, 0x01, 0x00, 0x04, 0x0E, 0x0C, 0x18, 0x0C, 0x0F, 0x07, 0x00, 0x00, 0x00, 0x0F, 0x0F, 0x00,
00250         0x00, 0x0F, 0x0F, 0x0F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0F, 0x0F, 0x00, 0x00, 0x00, 0x07,
00251         0x07, 0x0C, 0x0C, 0x18, 0x1C, 0x0C, 0x06, 0x06, 0x00, 0x04, 0x0E, 0x0C, 0x18, 0x0C, 0x0F, 0x07,
00252         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00253         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00254         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00255         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00256         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00257         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00258         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
00259         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
00260     };
00261 
00262     std::copy(
00263         &adaFruitLogo[0]
00264         , &adaFruitLogo[0] + (_rawHeight == 32 ? sizeof(adaFruitLogo)/2 : sizeof(adaFruitLogo))
00265         , buffer.begin()
00266     );
00267 #endif
00268 }
00269 
00270 /*
00271  *
00272  *   SPI specific implementation
00273  *
00274  */
00275 
00276 Adafruit_SSD1306_Spi::Adafruit_SSD1306_Spi(SPI &spi, PinName DC, PinName RST, PinName CS, uint8_t rawHieght, uint8_t rawWidth, bool flipVertical)
00277 : Adafruit_SSD1306(RST, rawHieght, rawWidth, flipVertical)
00278 , cs(CS,true)
00279 , dc(DC,false)
00280 , mspi(spi)
00281 {
00282     begin();
00283     splash();
00284     display();
00285 }
00286 
00287 void Adafruit_SSD1306_Spi::command(uint8_t c)
00288 {
00289     cs = 1;
00290     dc = 0;
00291     cs = 0;
00292     mspi.write(c);
00293     cs = 1;
00294 }
00295 
00296 void Adafruit_SSD1306_Spi::data(uint8_t c)
00297 {
00298     cs = 1;
00299     dc = 1;
00300     cs = 0;
00301     mspi.write(c);
00302     cs = 1;
00303 };
00304 
00305 void Adafruit_SSD1306_Spi::sendDisplayBuffer()
00306 {
00307     cs = 1;
00308     dc = 1;
00309     cs = 0;
00310 
00311     for(uint16_t i=0, q=buffer.size(); i<q; i++)
00312         mspi.write(buffer[i]);
00313 
00314     if(height() == 32)
00315     {
00316         for(uint16_t i=0, q=buffer.size(); i<q; i++)
00317             mspi.write(0);
00318     }
00319 
00320     cs = 1;
00321 }
00322 
00323 /*
00324  *
00325  *   I2C specific implementation
00326  *
00327  */
00328 
00329 Adafruit_SSD1306_I2c::Adafruit_SSD1306_I2c(I2C &i2c, PinName RST, uint8_t i2cAddress, uint8_t rawHeight, uint8_t rawWidth, bool flipVertical)
00330         : Adafruit_SSD1306(RST, rawHeight, rawWidth, flipVertical)
00331         , mi2c(i2c)
00332         , mi2cAddress(i2cAddress)
00333 {
00334     begin();
00335     splash();
00336     display();
00337 }
00338 
00339 void Adafruit_SSD1306_I2c::command(uint8_t c)
00340 {
00341     char buff[2];
00342     buff[0] = 0; // Command Mode
00343     buff[1] = c;
00344     mi2c.write(mi2cAddress, buff, sizeof(buff));
00345 }
00346 
00347 void Adafruit_SSD1306_I2c::data(uint8_t c)
00348 {
00349     char buff[2];
00350     buff[0] = 0x40; // Data Mode
00351     buff[1] = c;
00352     mi2c.write(mi2cAddress, buff, sizeof(buff));
00353 }
00354 
00355 void Adafruit_SSD1306_I2c::sendDisplayBuffer()
00356 {
00357     char buff[17];
00358     buff[0] = 0x40; // Data Mode
00359 
00360     // send display buffer in 16 byte chunks
00361     for(uint16_t i=0, q=buffer.size(); i<q; i+=16 )
00362     {   uint8_t x ;
00363 
00364         // TODO - this will segfault if buffer.size() % 16 != 0
00365         for(x=1; x<sizeof(buff); x++)
00366             buff[x] = buffer[i+x-1];
00367         mi2c.write(mi2cAddress, buff, sizeof(buff));
00368     }
00369 }