Added scrolling capability

Adafruit_SSD1306.cpp

@@ -110,6 +110,29 @@ static uint8_t buffer[SSD1306_LCDHEIGHT * SSD1306_LCDWIDTH / 8] = {
 
 #define ssd1306_swap(a, b) { int16_t t = a; a = b; b = t; }
 
+uint16_t Adafruit_SSD1306::getPixel(int16_t x, int16_t y) {
+  if ((x < 0) || (x >= width()) || (y < 0) || (y >= height()))
+    return BLACK;
+
+  // check rotation, move pixel around if necessary
+  switch (getRotation()) {
+  case 1:
+    ssd1306_swap(x, y);
+    x = WIDTH - x - 1;
+    break;
+  case 2:
+    x = WIDTH - x - 1;
+    y = HEIGHT - y - 1;
+    break;
+  case 3:
+    ssd1306_swap(x, y);
+    y = HEIGHT - y - 1;
+    break;
+  }
+
+  return (buffer[x+ (y/8)*SSD1306_LCDWIDTH] & (1 << (y&7)))? WHITE: BLACK;
+}
+
 // the most basic function, set a single pixel
 void Adafruit_SSD1306::drawPixel(int16_t x, int16_t y, uint16_t color) {
   if ((x < 0) || (x >= width()) || (y < 0) || (y >= height()))

Adafruit_SSD1306.h

@@ -66,8 +66,8 @@ All text above, and the splash screen must be included in any redistribution
     SSD1306_96_16
 
     -----------------------------------------------------------------------*/
-//   #define SSD1306_128_64
-   #define SSD1306_128_32
+   #define SSD1306_128_64
+//   #define SSD1306_128_32
 //   #define SSD1306_96_16
 /*=========================================================================*/
 
@@ -159,7 +159,8 @@ class Adafruit_SSD1306 : public Adafruit_GFX {
 
   void dim(boolean dim);
 
-  void drawPixel(int16_t x, int16_t y, uint16_t color);
+  uint16_t getPixel(int16_t x, int16_t y);
+  void     drawPixel(int16_t x, int16_t y, uint16_t color);
 
   virtual void drawFastVLine(int16_t x, int16_t y, int16_t h, uint16_t color);
   virtual void drawFastHLine(int16_t x, int16_t y, int16_t w, uint16_t color);

examples/ssd1306_128x64_spi_text_scroll/ssd1306_128x64_spi_text_scroll.ino

@@ -0,0 +1,72 @@
+/*********************************************************************
+This is an example for our Monochrome OLEDs based on SSD1306 drivers
+
+  Pick one up today in the adafruit shop!
+  ------> http://www.adafruit.com/category/63_98
+
+This example is for a 128x64 size display using SPI to communicate
+4 or 5 pins are required to interface
+
+Adafruit invests time and resources providing this open source code, 
+please support Adafruit and open-source hardware by purchasing 
+products from Adafruit!
+
+Written by Limor Fried/Ladyada  for Adafruit Industries.  
+BSD license, check license.txt for more information
+All text above, and the splash screen must be included in any redistribution
+*********************************************************************/
+
+#include <SPI.h>
+#include <Wire.h>
+#include <Adafruit_GFX.h>
+#include <Adafruit_SSD1306.h>
+
+// If using software SPI (the default case):
+#define OLED_MOSI   9
+#define OLED_CLK   10
+#define OLED_DC    11
+#define OLED_CS    12
+#define OLED_RESET 13
+Adafruit_SSD1306 display(OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);
+
+/* Uncomment this block to use hardware SPI
+#define OLED_DC     6
+#define OLED_CS     7
+#define OLED_RESET  8
+Adafruit_SSD1306 display(OLED_DC, OLED_RESET, OLED_CS);
+*/
+
+#if (SSD1306_LCDHEIGHT != 64)
+#error("Height incorrect, please fix Adafruit_SSD1306.h!");
+#endif
+
+int ii = 0;
+
+void setup()   {                
+  // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
+  display.begin(SSD1306_SWITCHCAPVCC);
+  // init done
+
+  // Setup text parameters
+  display.setTextSize(1);
+  display.setTextColor(WHITE);
+  display.setTextScroll(true);
+
+  // Show image buffer on the display hardware.
+  // Since the buffer is intialized with an Adafruit splashscreen
+  // internally, this will display the splashscreen.
+  display.display();
+  delay(1000);
+
+  // Clear the buffer.
+  display.clearDisplay();
+}
+
+
+void loop() {
+  display.print("Message #");
+  display.println(ii++);
+  display.display();
+  delay(1000);
+}
+