Diff: st7920.cpp

Revision:

0:1a97e0243dbc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/st7920.cpp	Fri Jun 29 22:47:51 2012 +0000
@@ -0,0 +1,246 @@
+#include "st7920.h"
+
+ST7920::ST7920 (PinName _RS,PinName _RW, PinName _E, PinName DB0, PinName DB1, PinName DB2, PinName DB3, PinName DB4, PinName DB5, PinName DB6, PinName DB7)
+        : DB(DB0,DB1,DB2,DB3,DB4,DB5,DB6,DB7),RS(_RS), RW(_RW), E(_E) {
+
+    DB.output();
+    E.write(0);
+    RS.write(0);
+    RW.write(0);
+    InitDisplay();
+}
+
+unsigned int ST7920::ByteReadLCD() {
+    unsigned int data;
+
+    DB.input();
+    E.write(1);
+    data = DB.read();
+    E.write(0);
+    DB.output();
+
+    return data;
+}
+
+void ST7920::ByteWriteLCD(unsigned int data) {
+    DB.output();
+    E.write(1);
+    DB.write(data);
+    E.write(0);
+}
+
+void ST7920::WriteInstruction(unsigned int Command) {
+    ReadBusyFlag();
+    RS.write(0);
+    RW.write(0);
+    ByteWriteLCD(Command);
+}
+
+void ST7920::WriteRAM(unsigned int data) {
+    ReadBusyFlag();
+    RS.write(1);
+    RW.write(0);
+    ByteWriteLCD(data);
+}
+
+void ST7920::ReadBusyFlag() {
+    unsigned char data;
+
+    RS.write(0);
+    RW.write(1);
+    while ((data & 0x7F) == BUSY_FLAG_BF) {
+        data = ByteReadLCD();
+    }
+}
+
+unsigned int ST7920::Read_AC() {
+    RS.write(0);
+    RW.write(1);
+    return (ByteReadLCD() & 0x7F);
+}
+
+unsigned int ST7920::ReadRAM() {
+    ReadBusyFlag();
+    RS.write(1);
+    RW.write(1);
+    return ByteReadLCD();
+}
+
+void ST7920::InitDisplay() {
+    wait_ms(40); // wait 40ms
+    E.write(0);
+    WriteInstruction(FUNCTION_SET | DATA_LENGTH_DL); // 8 bits interface, RE=0
+    wait_us(100); // wait 100us
+    WriteInstruction(FUNCTION_SET | DATA_LENGTH_DL); // again
+    wait_us(37); // wait 37us
+    WriteInstruction(DISPLAY_CONTROL | DISPLAY_ON_D ); // display on
+    wait_us(100); // wait 100us
+    WriteInstruction(DISPLAY_CLEAR); // clear display
+    wait_ms(10); // wait 10ms
+    WriteInstruction(ENTRY_MODE_SET | INCREASE_DECREASE_ID); // move cursor right
+    wait_ms(10); // wait 10ms
+    WriteInstruction(RETURN_HOME);
+    SetGraphicsMode();
+}
+
+//************************************************************************************************
+//public methodes
+void ST7920::SetGraphicsMode() {
+    WriteInstruction(EXTENDED_FUNCTION_SET | DATA_LENGTH_DL);
+    WriteInstruction(EXTENDED_FUNCTION_SET | DATA_LENGTH_DL | EXTENDED_INSTRUCTION_RE); //RE=1 (Extended funtion set)
+    WriteInstruction(EXTENDED_FUNCTION_SET | DATA_LENGTH_DL | EXTENDED_INSTRUCTION_RE | GRAPHIC_ON_G);
+}
+
+void ST7920::SetTextMode() {
+    WriteInstruction(FUNCTION_SET | DATA_LENGTH_DL); // RE=0 (Basic funtion set)
+}
+
+void ST7920::ClearScreen() {
+    WriteInstruction(FUNCTION_SET | DATA_LENGTH_DL); // RE=0 (Basic funtion set)
+    WriteInstruction(DISPLAY_CLEAR);
+}
+
+void ST7920::ReturnHome() {
+    WriteInstruction(FUNCTION_SET | DATA_LENGTH_DL); //RE=0 (Basic funtion set)
+    WriteInstruction(RETURN_HOME);
+}
+
+void ST7920::Standby() {
+    WriteInstruction(EXTENDED_FUNCTION_SET | DATA_LENGTH_DL | EXTENDED_INSTRUCTION_RE); //RE=1 (Extended funtion set)
+    WriteInstruction(STANDBY);
+}
+
+//Basic text functions
+void ST7920::DisplayString(int Row,int Column,unsigned char *ptr,int length) {
+    int i=0;
+
+    switch (Row) {
+        case 0:
+            Column|=0x80;
+            break;
+        case 1:
+            Column|=0x90;
+            break;
+        case 2:
+            Column|=0x88;
+            break;
+        case 3:
+            Column|=0x98;
+            break;
+        default:
+            Column=0x80;
+            break;
+    }
+
+    if (Column%2!=0) {
+        Column-=1;
+        i=1;
+    }
+    WriteInstruction((unsigned int)Column);
+
+    if (i==1) {
+        WriteRAM(' ');
+    }
+    for (i=0; i<length; i++) {
+        WriteRAM((unsigned int)ptr[i]);
+    }
+}
+
+void ST7920::DisplayChar(int Row,int Column,int inpChr) {
+    int i=0;
+
+    switch (Row) {
+        case 0:
+            Column|=0x80; // SET_DDRAM_ADDRESS
+            break;
+        case 1:
+            Column|=0x90;
+            break;
+        case 2:
+            Column|=0x88;
+            break;
+        case 3:
+            Column|=0x98;
+            break;
+        default:
+            Column=0x80;
+            break;
+    }
+
+    if (Column%2!=0) {
+        Column-=1;
+        i=1;
+    }
+    WriteInstruction((unsigned int)Column);
+
+    if (i==1) {
+        WriteRAM(' ');
+    }
+    WriteRAM((unsigned int)inpChr);
+}
+
+// Graphic functions
+void ST7920::FillGDRAM(unsigned char *bitmap) {
+    unsigned char i, j, k ;
+
+    for ( i = 0 ; i < 2 ; i++ ) {
+        for ( j = 0 ; j < 32 ; j++ ) {
+            WriteInstruction(SET_GRAPHIC_RAM_ADDRESS | j) ;
+            if ( i == 0 ) {
+                WriteInstruction(SET_GRAPHIC_RAM_ADDRESS) ;
+            } else {
+                WriteInstruction(SET_GRAPHIC_RAM_ADDRESS | 0x08) ;
+            }
+            for ( k = 0 ; k < 16 ; k++ ) {
+                WriteRAM( *bitmap++ ) ;
+            }
+        }
+    }
+}
+
+void ST7920::FillGDRAM_Turned(unsigned char *bitmap) {
+    int i, j, k, m, offset_row, mask ;
+    unsigned char data;
+
+    for ( i = 0 ; i < 2 ; i++ ) { //upper and lower page
+        for ( j = 0 ; j < 32 ; j++ ) { //32 lines per page
+            WriteInstruction(SET_GRAPHIC_RAM_ADDRESS | j) ;
+            if ( i == 0 ) {
+                WriteInstruction(SET_GRAPHIC_RAM_ADDRESS) ;
+            } else {
+                WriteInstruction(SET_GRAPHIC_RAM_ADDRESS | 0x08) ;
+            }
+            mask=1<<(j%8); // extract bitnumber
+            //printf("mask: %d\r\n",mask);
+            for ( k = 0 ; k < 16 ; k++ ) { //16 bytes per line
+                offset_row=((i*32+j)/8)*128 + k*8; //y coordinate/8 = row 0-7 * 128 = byte offset, read 8 bytes
+                data=0;
+                for (m = 0 ; m < 8 ; m++) { // read 8 bytes from source
+
+                    if ((bitmap[offset_row+m] & mask)) { //pixel = 1
+                        data|=(128>>m);
+                    }
+                }
+                WriteRAM(data) ;
+            }
+        }
+    }
+}
+
+void ST7920::ClearGDRAM() {
+    unsigned char i, j, k ;
+
+    for ( i = 0 ; i < 2 ; i++ ) {
+        for ( j = 0 ; j < 32 ; j++ ) {
+            WriteInstruction(SET_GRAPHIC_RAM_ADDRESS | j) ;
+            if ( i == 0 ) {
+                WriteInstruction(SET_GRAPHIC_RAM_ADDRESS) ;
+            } else {
+                WriteInstruction(SET_GRAPHIC_RAM_ADDRESS | 0x08) ;
+            }
+            for ( k = 0 ; k < 16 ; k++ ) {
+                WriteRAM(0);
+            }
+        }
+    }
+}