SSD1306_mini.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 Jiri Stepanovsky 6/4/2018 for LPE compatibility
00022  */
00023 
00024 #include "mbed.h"
00025 #include "SSD1306_mini.h"
00026 
00027 #define SSD1306_SETCONTRAST 0x81
00028 #define SSD1306_DISPLAYALLON_RESUME 0xA4
00029 #define SSD1306_DISPLAYALLON 0xA5
00030 #define SSD1306_NORMALDISPLAY 0xA6
00031 #define SSD1306_INVERTDISPLAY 0xA7
00032 #define SSD1306_DISPLAYOFF 0xAE
00033 #define SSD1306_DISPLAYON 0xAF
00034 #define SSD1306_SETDISPLAYOFFSET 0xD3
00035 #define SSD1306_SETCOMPINS 0xDA
00036 #define SSD1306_SETVCOMDETECT 0xDB
00037 #define SSD1306_SETDISPLAYCLOCKDIV 0xD5
00038 #define SSD1306_SETPRECHARGE 0xD9
00039 #define SSD1306_SETMULTIPLEX 0xA8
00040 #define SSD1306_SETLOWCOLUMN 0x00
00041 #define SSD1306_SETHIGHCOLUMN 0x10
00042 #define SSD1306_SETSTARTLINE 0x40
00043 #define SSD1306_MEMORYMODE 0x20
00044 #define SSD1306_COMSCANINC 0xC0
00045 #define SSD1306_COMSCANDEC 0xC8
00046 #define SSD1306_SEGREMAP 0xA0
00047 #define SSD1306_CHARGEPUMP 0x8D
00048 
00049 void SSD1306_mini::begin(uint8_t vccstate)
00050 {
00051     rst = 1;
00052     // VDD (3.3V) goes high at start, lets just chill for a ms
00053     wait_ms(1);
00054     // bring reset low
00055     rst = 0;
00056     // wait 10ms
00057     wait_ms(10);
00058     // bring out of reset
00059     rst = 1;
00060     // turn on VCC (9V?)
00061 
00062     command(SSD1306_DISPLAYOFF);
00063     command(SSD1306_SETDISPLAYCLOCKDIV);
00064     command(0x80);                                  // the suggested ratio 0x80
00065 
00066     command(SSD1306_SETMULTIPLEX);
00067     command(OLED_HEIGHT-1);
00068 
00069     command(SSD1306_SETDISPLAYOFFSET);
00070     command(0x0);                                   // no offset
00071 
00072     command(SSD1306_SETSTARTLINE | 0x0);            // line #0
00073 
00074     command(SSD1306_CHARGEPUMP);
00075     command((vccstate == SSD1306_EXTERNALVCC) ? 0x10 : 0x14);
00076 
00077     command(SSD1306_MEMORYMODE);
00078     command(0x00);                                  // 0x0 act like ks0108
00079 
00080     command(SSD1306_SEGREMAP | 0x1);
00081 
00082     command(SSD1306_COMSCANDEC);
00083 
00084     command(SSD1306_SETCOMPINS);
00085     command(OLED_HEIGHT == 32 ? 0x02 : 0x12);        // TODO - calculate based on _rawHieght ?
00086 
00087     command(SSD1306_SETCONTRAST);
00088     command(OLED_HEIGHT == 32 ? 0x8F : ((vccstate == SSD1306_EXTERNALVCC) ? 0x9F : 0xCF) );
00089 
00090     command(SSD1306_SETPRECHARGE);
00091     command((vccstate == SSD1306_EXTERNALVCC) ? 0x22 : 0xF1);
00092 
00093     command(SSD1306_SETVCOMDETECT);
00094     command(0x40);
00095 
00096     command(SSD1306_DISPLAYALLON_RESUME);
00097 
00098     command(SSD1306_NORMALDISPLAY);
00099     
00100     command(SSD1306_DISPLAYON);
00101 }
00102 
00103 // Set a single pixel
00104 void SSD1306_mini::drawPixel(int16_t x, int16_t y, uint16_t color)
00105 {
00106     if ((x < 0) || (x >= OLED_WIDTH) || (y < 0) || (y >= OLED_HEIGHT))
00107         return;
00108     // x is which column
00109     if (color == WHITE) 
00110         buffer[x+ (y/8)*OLED_WIDTH] |= 1<<(y%8);  
00111     else // else black
00112         buffer[x+ (y/8)*OLED_WIDTH] &= ~(1<<(y%8)); 
00113 }
00114 
00115 void SSD1306_mini::invertDisplay(bool i)
00116 {
00117     command(i ? SSD1306_INVERTDISPLAY : SSD1306_NORMALDISPLAY);
00118 }
00119 
00120 // Send the display buffer out to the display
00121 void SSD1306_mini::display(void)
00122 {
00123     command(SSD1306_SETLOWCOLUMN | 0x0);  // low col = 0
00124     command(SSD1306_SETHIGHCOLUMN | 0x0);  // hi col = 0
00125     command(SSD1306_SETSTARTLINE | 0x0); // line #0
00126     sendDisplayBuffer();
00127 }
00128 
00129 // Clear the display buffer. Requires a display() call at some point afterwards
00130 void SSD1306_mini::clearDisplay(void)
00131 {
00132     for(uint16_t i=0, q=OLED_BUFFER_SIZE; i<q; i++)
00133         buffer[i] = 0;
00134 }