From 9347d62332eb7ff43725021c773fd9251d67d6ba Mon Sep 17 00:00:00 2001
From: Phillip Burgess <paintyourdragon@dslextreme.com>
Date: Wed, 15 Jan 2014 20:46:57 -0800
Subject: [PATCH] Fixed double writes; tested on 128x64 and 128x32 SPI displays

---
 Adafruit_SSD1306.cpp | 31 +++++++------------------------
 Adafruit_SSD1306.h   |  5 ++---
 2 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/Adafruit_SSD1306.cpp b/Adafruit_SSD1306.cpp
index bdae4e9..4fd6599 100644
--- a/Adafruit_SSD1306.cpp
+++ b/Adafruit_SSD1306.cpp
@@ -383,9 +383,13 @@ void Adafruit_SSD1306::ssd1306_data(uint8_t c) {
 }
 
 void Adafruit_SSD1306::display(void) {
-  ssd1306_command(SSD1306_SETLOWCOLUMN | 0x0);  // low col = 0
-  ssd1306_command(SSD1306_SETHIGHCOLUMN | 0x0);  // hi col = 0
-  ssd1306_command(SSD1306_SETSTARTLINE | 0x0); // line #0
+  ssd1306_command(SSD1306_COLUMNADDR);
+  ssd1306_command(0);   // Column start address (0 = reset)
+  ssd1306_command(127); // Column end address (127 = reset)
+
+  ssd1306_command(SSD1306_PAGEADDR);
+  ssd1306_command(0); // Page start address (0 = reset)
+  ssd1306_command((SSD1306_LCDHEIGHT == 64) ? 7 : 3); // Page end address
 
   if (sid != -1)
   {
@@ -398,13 +402,6 @@ void Adafruit_SSD1306::display(void) {
       fastSPIwrite(buffer[i]);
       //ssd1306_data(buffer[i]);
     }
-    // i wonder why we have to do this (check datasheet)
-    if (SSD1306_LCDHEIGHT == 32) {
-      for (uint16_t i=0; i<(SSD1306_LCDWIDTH*SSD1306_LCDHEIGHT/8); i++) {
-        //ssd1306_data(0);
-        fastSPIwrite(0);
-      }
-    }
     *csport |= cspinmask;
   }
   else
@@ -428,20 +425,6 @@ void Adafruit_SSD1306::display(void) {
       i--;
       Wire.endTransmission();
     }
-    // i wonder why we have to do this (check datasheet)
-    if (SSD1306_LCDHEIGHT == 32) {
-      for (uint16_t i=0; i<(SSD1306_LCDWIDTH*SSD1306_LCDHEIGHT/8); i++) {
-	// send a bunch of data in one xmission
-	Wire.beginTransmission(_i2caddr);
-	Wire.write(0x40);
-	for (uint8_t x=0; x<16; x++) {
-	  Wire.write((uint8_t)0x00);
-	  i++;
-	}
-	i--;
-	Wire.endTransmission();
-      }
-    }
     TWBR = twbrbackup;
   }
 }
diff --git a/Adafruit_SSD1306.h b/Adafruit_SSD1306.h
index ae57ddc..126e36f 100644
--- a/Adafruit_SSD1306.h
+++ b/Adafruit_SSD1306.h
@@ -42,9 +42,6 @@ All text above, and the splash screen must be included in any redistribution
 
     SSD1306_128_32  128x32 pixel display
 
-    You also need to set the LCDWIDTH and LCDHEIGHT defines to an 
-    appropriate size
-
     -----------------------------------------------------------------------*/
    #define SSD1306_128_64
 //   #define SSD1306_128_32
@@ -90,6 +87,8 @@ All text above, and the splash screen must be included in any redistribution
 #define SSD1306_SETSTARTLINE 0x40
 
 #define SSD1306_MEMORYMODE 0x20
+#define SSD1306_COLUMNADDR 0x21
+#define SSD1306_PAGEADDR   0x22
 
 #define SSD1306_COMSCANINC 0xC0
 #define SSD1306_COMSCANDEC 0xC8