main.cpp

00001 #include "mbed.h"
00002 
00003 #define DISPLAY_RESET   D0
00004 
00005 #define SSD1306_LCDWIDTH      128 
00006 #define SSD1306_LCDHEIGHT      64 
00007 #define SSD1306_SETCONTRAST   0x81 
00008 #define SSD1306_DISPLAYALLON_RESUME 0xA4 
00009 #define SSD1306_DISPLAYALLON 0xA5 
00010 #define SSD1306_NORMALDISPLAY 0xA6 
00011 #define SSD1306_INVERTDISPLAY 0xA7 
00012 #define SSD1306_DISPLAYOFF 0xAE 
00013 #define SSD1306_DISPLAYON 0xAF 
00014 #define SSD1306_SETDISPLAYOFFSET 0xD3 
00015 #define SSD1306_SETCOMPINS 0xDA 
00016 #define SSD1306_SETVCOMDETECT 0xDB 
00017 #define SSD1306_SETDISPLAYCLOCKDIV 0xD5 
00018 #define SSD1306_SETPRECHARGE 0xD9 
00019 #define SSD1306_SETMULTIPLEX 0xA8 
00020 #define SSD1306_SETLOWCOLUMN 0x00 
00021 #define SSD1306_SETHIGHCOLUMN 0x10 
00022 #define SSD1306_SETSTARTLINE 0x40 
00023 #define SSD1306_MEMORYMODE 0x20 
00024 #define SSD1306_COLUMNADDR 0x21 
00025 #define SSD1306_PAGEADDR   0x22 
00026 #define SSD1306_COMSCANINC 0xC0 
00027 #define SSD1306_COMSCANDEC 0xC8 
00028 #define SSD1306_SEGREMAP 0xA0 
00029 #define SSD1306_CHARGEPUMP 0x8D 
00030 #define SSD1306_EXTERNALVCC 0x1 
00031 #define SSD1306_SWITCHCAPVCC 0x2
00032 
00033  I2C i2c(I2C_SDA, I2C_SCL);
00034 
00035 char _i2c_address; 
00036 char display_buffer[1024];
00037 
00038 void ssd1306_command(char c){
00039     char control = 0x00;
00040     i2c.start();
00041     i2c.write(_i2c_address);
00042     i2c.write(control);
00043     i2c.write(c);
00044     i2c.stop();   
00045 }
00046 
00047 void ssd1306_data(char c){
00048     i2c.start();
00049     i2c.write(_i2c_address);
00050     i2c.write(0x40);
00051     i2c.write(c);
00052     i2c.stop();
00053 }
00054 
00055 void setColAddress() 
00056 { 
00057   ssd1306_command(SSD1306_COLUMNADDR); // 0x21 COMMAND 
00058   ssd1306_command(0); // Column start address 
00059   ssd1306_command(SSD1306_LCDWIDTH-1); // Column end address 
00060 } 
00061 
00062 void setPageAddress() 
00063 { 
00064   ssd1306_command(SSD1306_PAGEADDR); // 0x22 COMMAND 
00065   ssd1306_command(0); // Start Page address 
00066   ssd1306_command((SSD1306_LCDHEIGHT/8)-1);// End Page address 
00067 } 
00068 
00069 void TransferBuffer() 
00070 { 
00071   int j=0; 
00072   
00073       // set the Column and Page addresses to 0,0 
00074       setColAddress(); 
00075       setPageAddress(); 
00076         
00077       i2c.start(); 
00078       i2c.write(_i2c_address); 
00079       i2c.write(0X40); // data not command 
00080       for(j=0;j<1024;j++) 
00081       { 
00082         i2c.write(display_buffer[j]); 
00083       } 
00084 
00085       i2c.stop(); 
00086 } 
00087 
00088 void InitializeDisplay()
00089 {
00090     DigitalOut(DISPLAY_RESET,1);
00091     // VDD (3.3V) goes high at start, lets just chill for a ms
00092     wait_ms(1);
00093     // bring reset low
00094     DigitalOut(DISPLAY_RESET,0);
00095     // wait 10ms
00096     wait_ms(10);
00097     // bring out of reset
00098     DigitalOut(DISPLAY_RESET,1);
00099     // turn on VCC (9V?)
00100 
00101 // Init sequence for 128x64 OLED module 
00102     ssd1306_command(SSD1306_DISPLAYOFF);                    // 0xAE 
00103 
00104     ssd1306_command(SSD1306_SETDISPLAYCLOCKDIV);            // 0xD5 
00105     ssd1306_command(0x80);                 // the suggested ratio 0x80 
00106     
00107     ssd1306_command(SSD1306_SETMULTIPLEX);                  // 0xA8 
00108     ssd1306_command(0x3F); 
00109     
00110     ssd1306_command(SSD1306_SETDISPLAYOFFSET);              // 0xD3 
00111     ssd1306_command(0x0);                                   // no offset 
00112     
00113     ssd1306_command(SSD1306_SETSTARTLINE);// | 0x0);        // line #0 
00114     
00115     ssd1306_command(SSD1306_CHARGEPUMP);                    // 0x8D 
00116     ssd1306_command(0x14);  // using internal VCC 
00117     
00118     ssd1306_command(SSD1306_MEMORYMODE);                    // 0x20 
00119     ssd1306_command(0x00);          // 0x00 horizontal addressing 
00120     
00121     ssd1306_command(SSD1306_SEGREMAP | 0x1); // rotate screen 180 
00122     
00123     ssd1306_command(SSD1306_COMSCANDEC); // rotate screen 180 
00124     
00125     ssd1306_command(SSD1306_SETCOMPINS);                    // 0xDA 
00126     ssd1306_command(0x12); 
00127     
00128     ssd1306_command(SSD1306_SETCONTRAST);                   // 0x81 
00129     ssd1306_command(0xCF); 
00130     
00131     ssd1306_command(SSD1306_SETPRECHARGE);                  // 0xd9 
00132     ssd1306_command(0xF1); 
00133     
00134     ssd1306_command(SSD1306_SETVCOMDETECT);                 // 0xDB 
00135     ssd1306_command(0x40); 
00136     
00137     ssd1306_command(SSD1306_DISPLAYALLON_RESUME);           // 0xA4 
00138     
00139     ssd1306_command(SSD1306_NORMALDISPLAY);                 // 0xA6 
00140   
00141     ssd1306_command(SSD1306_DISPLAYON);                     //switch on OLED
00142 }
00143 
00144 int main() {
00145     
00146     // fill buffer with something for test 
00147     memset( display_buffer, 0X02, 1024); // tried other values
00148     
00149     _i2c_address = 0x78;
00150     
00151     InitializeDisplay();
00152     
00153     TransferBuffer(); // try sending buffer 
00154     
00155     while(1) 
00156    { 
00157      wait_ms(1000); // keyboard code here 
00158      if(DigitalIn(LED1) == 0){DigitalOut(LED1,1);}
00159      else{DigitalOut(LED1,0);}
00160    } 
00161 }