/**************************************************************************** ** ** ** Hitachi Character-Type LCD Display ** ** ** ****************************************************************************/ // // NOTE: This is set up for 4 MHz oscillator // #define LCD_C // "I am LCD.C" #ifndef CLRWDT #include <pic.h> #endif #include "defs.h" #include "lcd.h" #include "delay.h" // Contains delay routines & macros const byte const LCD_ROW_ADDRESS[] = // Row/Column information for lcd_gotoxy() { #if LCD_MODE_1x8 0x00 #endif #if LCD_MODE_1x16_A 0x00 #endif #if LCD_MODE_1x16_B 0x00, 0x40 #endif #if LCD_MODE_1x40 0x00, #endif #if LCD_MODE_2x8 0x00, 0x40 #endif #if LCD_MODE_2x12 0x00, 0x40 #endif #if LCD_MODE_2x16 0x00, 0x40 #endif #if LCD_MODE_2x20 0x00, 0x40 #endif #if LCD_MODE_2x24 0x00, 0x40 #endif #if LCD_MODE_2x40 0x00, 0x40 #endif #if LCD_MODE_4x16 0x00, 0x40, 0x10, 0x50 #endif #if LCD_MODE_4x20 0x00, 0x40, 0x14, 0x54 #endif #if LCD_MODE_4x24 0x00, 0x40, 0x80, 0xc0 #endif }; const byte const LCD_INIT_STRING [] = // LCD Init String on powerup { 0b00000001, // Clear display 0b00000010, // Home cursor 0b00000100 // Entry Mode #if LCD_CURSOR_INCREMENT | 0b00000010 // Increment cursor #endif #if LCD_CURSOR_SHIFT | 0b00000001 // Shift on cursor #endif , // end 0b00001000 // Display Control #if LCD_DISPLAY_ON | 0b00000100 // Display on #endif #if LCD_CURSOR_ON | 0b00000010 // Cursor on #endif #if LCD_CURSOR_BLINK | 0b00000001 // Blink on #endif , // end 0b00100000 // Function Set #if LCD_8_BIT_MODE | 0b00010000 // 8-bit data bus #endif #if LCD_MULTI_LINE | 0b00001000 // 2-line refreshing #endif #if LCD_DISPLAY_5x10 | 0b00000100 // 5x10 matrix #endif }; #if LCD_4_BIT_MODE void lcd_putnybble (byte c) // Write nybble to port in current RS mode { c = c << LCD_D4_BIT; // Shift over to correct bit column c &= LCD_TRIS_DATAMASK; // Remove any extraneous bits LCD_DATA_PORT = (LCD_DATA_PORT & ~LCD_TRIS_DATAMASK) | c; // Write data bits to port delay_uS (1); LCD_E = 1; // Start to write it delay_uS (2); LCD_E = 0; // Finish write cycle } #endif byte lcd_getbyte (void) // Read byte at cursor (RS=1) or ready status (RS=0) { byte retval; #if LCD_4_BIT_MODE byte highbits; LCD_TRIS_PORT |= LCD_TRIS_DATAMASK; // Set port to read mode for data pins LCD_RW = 1; // Tell LCD we want to read delay_uS (1); LCD_E = 1; highbits = (((LCD_DATA_PORT & LCD_TRIS_DATAMASK) >> LCD_D4_BIT) << 4);// Grab high bits and shift to right place LCD_E = 0; delay_uS (1); LCD_E = 1; delay_uS (1); retval = ((LCD_DATA_PORT & LCD_TRIS_DATAMASK) >> LCD_D4_BIT); // Grab low bits LCD_E = 0; retval |= highbits; LCD_TRIS_PORT &= ~LCD_TRIS_DATAMASK; // Set port back to output mode #else LCD_TRIS_PORT = 0xFF; // Set port to all input LCD_RW = 1; // Tell LCD we want to read delay_uS (1); LCD_E = 1; // Do the read delay_uS (1); retval = LCD_DATA_PORT; LCD_E = 0; LCD_TRIS_PORT = 0x00; // Set port back to outputs #endif return (retval); // Give answer to caller } void lcd_putbyte (byte c) // Write byte to port in current RS mode { byte RS_Status; RS_Status = LCD_RS; // Get old pin state LCD_RS = 0; // Force into command mode to read state while (lcd_getbyte () & 0x80); // Wait for read state if (RS_Status) LCD_RS = 1; // Restore RS to old state delay_uS (1); LCD_RW = 0; // Set to write mode delay_uS (1); #if LCD_4_BIT_MODE lcd_putnybble (c >> 4); // Send the character out lcd_putnybble (c); #else LCD_DATA_PORT = c; // Send the character out #endif LCD_E = 1; delay_uS (1); LCD_E = 0; } void lcd_command (byte c) // Send command to LCD port { LCD_RS = 0; lcd_putbyte (c); } #if LCD_ALLOW_USER_CHARS void lcd_define_char (byte c, const byte *bitmap) // Define user-defined chars { byte i; lcd_command ((0b01000000) | (c << 3)); // Select char to define LCD_RS = 1; for (i = 0; i < 8; i++) lcd_putbyte (*bitmap++); // Put in each byte of memory } #endif byte lcd_lineof (byte CursorAddress) // Calculate cursor row from it's address { CursorAddress &= 0x50; // Strips out uniquely the address bits switch (CursorAddress) { case 0x00: // Note - this handles all cases except for some CursorAddress = 1; // of those unsupported displays listed in case 0x40: // lcd.h file. #if LCD_MODE_1x16_B CursorAddress = 1; // Only 1 row this type of display #else CursorAddress = 2; #endif case 0x10: CursorAddress = 3; case 0x50: CursorAddress = 4; default: CursorAddress = 1; } return (CursorAddress); } byte lcd_cursorpos (void) // Return address of cursor position { LCD_RS = 0; return (lcd_getbyte ()); // Get cursor position } void lcd_putc (byte c) // Write character to LCD { #if !LCD_ALLOW_USER_CHARS byte CursAddr; #endif #if LCD_ALLOW_USER_CHARS // Allow user-defined characters - no terminal mode LCD_RS = 1; lcd_putbyte (c); #else switch (c) { case '\b': // Backspace? lcd_command (LCD_COMMAND_BACKSPACE); // back cursor up #if LCD_DESTRUCTIVE_BS LCD_RS = 1; // set display mode lcd_putbyte (' '); // erase previous character lcd_command (LCD_COMMAND_BACKSPACE); // move cursor back again #endif break; case '\n': // Newline? RS = 0; CursAddr = lcd_getbyte (); // Get cursor position CursAddr = lcd_lineof (CursAddr); #if LCD_ENABLE_SCROLL if (CursAddr >= LCD_MAXROWS) // Bottom line? lcd_scroll (); // Yes, force scroll else // No, just go to start of next line lcd_gotoxy (CursAddr+1,1); #else lcd_gotoxy (CursAddr+1, 1); // Position cursor to start of line #endif break; case '\f': // Form Feed (clear screen)? lcd_command (LCD_COMMAND_CLEAR); // Erase screen lcd_gotoxy (1,1); // Position cursor to top of screen break; default: // Printable? LCD_RS = 1; // Set to display mode lcd_putbyte (c); // Send character out } #endif } #if LCD_ENABLE_GETC byte lcd_getc (void) // Read character at cursor { byte retval; LCD_RS = 1; retval = lcd_getbyte (); LCD_RS = 0; return (retval); } #endif #if LCD_ENABLE_GOTOXY void lcd_gotoxy (byte row, byte col) // Position cursor { #if LCD_MODE_1x16_B if (col > 7) // 1x16 is treated the same as 2x8 for addressing { row++; col -= 8; } if (col > 8) col = 8; if (row > 2) row = 2; #else if (row > LCD_MAXROWS) // Range limit row = LCD_MAXROWS; if (col > LCD_MAXCOLS) col = LCD_MAXCOLS; #endif row = LCD_ROW_ADDRESS[row-1]; // Get address of first byte on desired row row += col - 1; lcd_command (0x80 | row); // Write new cursor address } void lcd_getxy (byte *row, byte *col) // Return row and column of cursor position { byte rr, cc; cc = lcd_cursorpos (); rr = lcd_lineof (cc); // Get row of the cursor cc = (cc & 0x7f) - LCD_ROW_ADDRESS[rr-1]; // Find the column *row = rr; // Convert to lcd_gotoxy() units *col = cc; } #endif #if LCD_ENABLE_PRINTF void lcd_printf (const char* message) // Write message to LCD (C string type) { while (*message) // Look for end of string lcd_putc (*message++); // Show and bump } #endif #if LCD_ENABLE_SCROLL void lcd_scroll (void) // Scroll up one line { byte CursorPos, // Hold position of cursor Character, // Hold character being moved SrcAddr, // Source Address DestAddr, // Destination Address EndAddr; // Ending copy address (last address of Source) LCD_RS = 0; CursorPos = lcd_getbyte () | 0x80; // Get cursor position lcd_gotoxy (2,1); LCD_RS = 0; SrcAddr = lcd_getbyte () | 0x80; // Find address of copy start lcd_gotoxy (1,1); LCD_RS = 0; DestAddr = lcd_getbyte () | 0x80; // Find address of copy destination lcd_gotoxy (LCD_MAXROWS, LCD_MAXCOLS); LCD_RS = 0; EndAddr = lcd_getbyte () | 0x80; // Find address of last byte to copy over do { LCD_RS = 0; // Position to source of copy char lcd_putbyte (SrcAddr); LCD_RS = 1; Character = lcd_getbyte (); // Read the character there LCD_RS = 0; lcd_putbyte (DestAddr); // Move to the destination LCD_RS = 1; lcd_putbyte (Character); // Write it the char there SrcAddr++; DestAddr++; } while (SrcAddr <= EndAddr); // Loop through all memory for (Character = 1; Character <= LCD_MAXCOLS; Character++) { lcd_gotoxy (LCD_MAXROWS, Character); // Position on last line lcd_putc (' '); // Blank out the char } lcd_gotoxy (lcd_lineof (CursorPos) + 1,1); // Home cursor next line } #endif #if LCD_ENABLE_UNSCROLL void lcd_unscroll (void) // Roll scroll backwards one line { byte CursorPos, // Hold position of cursor Character, // Hold character being moved SrcAddr, // Source Address DestAddr; // Destination Address LCD_RS = 0; CursorPos = lcd_getbyte () | 0x80; // Get cursor position lcd_gotoxy (LCD_MAXROWS-1,LCD_MAXCOLS); LCD_RS = 0; SrcAddr = lcd_getbyte () | 0x80; // Find address of copy start lcd_gotoxy (LCD_MAXROWS,LCD_MAXCOLS); LCD_RS = 0; DestAddr = lcd_getbyte () | 0x80; // Find address of copy destination do { LCD_RS = 0; // Position to source of copy char lcd_putbyte (SrcAddr); LCD_RS = 1; Character = lcd_getbyte (); // Read the character there LCD_RS = 0; lcd_putbyte (DestAddr); // Move to the destination LCD_RS = 1; lcd_putbyte (Character); // Write it the char there SrcAddr--; DestAddr--; } while (SrcAddr != 0x80); // Loop through all memory for (Character = 0; Character < LCD_MAXCOLS; Character++) { lcd_gotoxy (1, Character); // Position on top row lcd_putc (' '); // Blank out the char } lcd_gotoxy (lcd_lineof (CursorPos),1); // Home cursor same line as before } #endif #if LCD_ENABLE_CLEAR void lcd_clear (void) // Clear LCD screen { lcd_command (LCD_COMMAND_CLEAR); } #endif void lcd_init (void) // Reset display from software { byte i; LCD_E = 0; // Set up control pin I/O LCD_TRIS_E = 0; LCD_RW = 0; // Write mode LCD_TRIS_RW = 0; LCD_RS = 0; // Command mode LCD_TRIS_RS = 0; LCD_TRIS_PORT &= ~LCD_TRIS_DATAMASK; // Set data bus to output LCD_E = 0; // Start talking to LCD delay_mS (15); // Wait a little while #if LCD_4_BIT_MODE // Set LCD into 4-bit mode lcd_putnybble (0b0011); // Select 8-bit mode delay_mS (5); // Spec calls for 4.1 mS lcd_putnybble (0b0011); // Do it again delay_uS (100); lcd_putnybble (0b0011); lcd_putnybble (0b0010); // Off and running... #else lcd_putbyte (0b00110000); // Select 8-bit mode delay_mS (5); // Spec calls for 4.1 mS lcd_putbyte (0b00110000); // Do it again delay_uS (100); lcd_putbyte (0b00110000); lcd_putbyte (0b00110000); // Off and running... #endif for (i = 0; i < sizeof(LCD_INIT_STRING); i++) // Send other LCD initialization stuff lcd_command (LCD_INIT_STRING[i]); }
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