lcd.cpp

00001 #include "lcd.h "
00002 
00003 BusOut LcdDB(p21, p22, p23, p24, p25, p26, p27, p28);
00004 DigitalOut LcdRS(p18);
00005 DigitalOut LcdRW(p19);
00006 DigitalOut LcdEN(p20);
00007 
00008 #define bit_set(p,m) ((p) |= (1<<m))
00009 #define bit_clear(p,m) ((p) &= ~(1<<m)) 
00010 
00011 /* Delays needed to use the LCD */
00012 #define COMMAND_DELAY 15  // ns
00013 #define SHORT_DELAY   10  // us
00014 #define LONG_DELAY    100 // ms
00015 #define STARTDELAY    50  // ms
00016 
00017 gfxLcd::gfxLcd()
00018 {
00019     init();
00020 }
00021 
00022 void gfxLcd::init()
00023 {
00024     // Set all to low
00025     LcdDB = 0x00;
00026     LcdRS = 0x00;
00027     LcdRW = 0x00;
00028     LcdEN = 0x00;
00029     
00030     wait_ms(STARTDELAY);
00031     
00032     // TODO: Try if the amount of commands could be reduced
00033     //       and delays shortened
00034     
00035     // Specify 8 bit interface and basic instruction set
00036     write(0, 0x30);
00037     wait_us(LONG_DELAY); 
00038     // Specify 8 bit interface and basic instruction set
00039     write(0, 0x30);
00040     wait_us(SHORT_DELAY);
00041     // Specify Display on, Cursor off and Blink off
00042     write(0, 0x0C);
00043     wait_us(SHORT_DELAY);
00044     // Display clear.
00045     write(0, 0x01); 
00046     wait_ms(SHORT_DELAY);
00047     // AC Increase (cursor move right), don't shift the display
00048     write(0, 0x06); 
00049     wait_us(SHORT_DELAY);
00050     // Select extended instruction set
00051     write(0, 0x34);
00052     wait_us(SHORT_DELAY);
00053     // Graphic display ON
00054     write(0, 0x36);
00055 
00056     fillScreen(false);
00057     update(); // Refresh display
00058 }
00059 
00060 void gfxLcd::write(bool rs, char c)
00061 { 
00062     // Writes an instruction/data to the LCD   
00063     LcdRS = rs;
00064     wait_us(SHORT_DELAY); 
00065     LcdRW = 0;
00066     wait_us(SHORT_DELAY);
00067     LcdEN = 0;
00068     LcdDB = c;
00069     wait_us(SHORT_DELAY);
00070     LcdEN = 1;
00071     wait_us(COMMAND_DELAY); 
00072     LcdEN = 0; 
00073 } 
00074 
00075 void gfxLcd::fillScreen(bool color)
00076 { 
00077   char v, h; 
00078   uint32_t d; 
00079 
00080   d = (color == true ? 0xFFFFL : 0x0000L); 
00081 
00082   for (v=0; v<32; v++) 
00083   { 
00084     for (h=0; h<160; h++) 
00085     { 
00086       fbuf.dots[v][h].word = d; 
00087     } 
00088   } 
00089   fbuf.refresh = true; 
00090 }
00091 
00092 void gfxLcd::putPixel(char x, char y, bool color)
00093 { 
00094     uint32_t v, h, b;
00095 
00096     v = y;
00097     h = x/16;
00098     b = 15 - (x%16); 
00099 
00100     // Modify the actual word
00101     if (color == true)
00102         bit_set(fbuf.dots[v][h].word, b);
00103     else
00104         bit_clear(fbuf.dots[v][h].word, b); 
00105   
00106     fbuf.refresh = true; 
00107 } 
00108 
00109 void gfxLcd::update()
00110 {
00111     char v, h; 
00112     
00113     if (fbuf.refresh == true) 
00114     { 
00115         for (v=0; v<32; v++) 
00116         { 
00117             write(0, 0x80 | v); // Set Vertical Address
00118             write(0, 0x80 | 0); // Set Horizontal Address
00119 
00120             for (h=0; h<10; h++) 
00121             {
00122                 write(1, fbuf.dots[v][h].byte[1]); // Write High Byte
00123                 write(1, fbuf.dots[v][h].byte[0]); // Write Low Byte
00124             }
00125         }
00126         fbuf.refresh = false; 
00127     }
00128 }