Diff: TextLCD_20X4.cpp

Revision:

1:c5f7996b1035

Parent:

0:f84245f91a5a

--- a/TextLCD_20X4.cpp	Fri May 14 21:19:39 2010 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,170 +0,0 @@
-/* mbed TextLCD Library
- * Copyright (c) 2007-2009 sford
- * Released under the MIT License: http://mbed.org/license/mit
- *
- * TODO: Needs serious rework/neatening up!
- */
-
-/*
- *  2010/05/14 modified for 20X4 LCD by ym1784
- */
-
-#include "TextLCD_20X4.h"
-
-#include "mbed.h"
-#include "error.h"
-
-using namespace mbed;
-
-/*
- * useful info found at http://www.a-netz.de/lcd.en.php
- *
- *
- * Initialization
- * ==============
- *
- * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state
- *
- * - wait approximately 15 ms so the display is ready to execute commands
- * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now).
- * - The display is in 8 bit mode, so if you have only connected 4 data pins you should only transmit the higher nibble of each command.
- * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now.
- * - Execute the "clear display" command
- *
- * Timing
- * ======
- *
- * Nearly all commands transmitted to the display need 40us for execution.
- * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position"
- * These commands need 1.64ms for execution. These timings are valid for all displays working with an
- * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you
- * can use the busy flag to test if the display is ready to accept the next command.
- *
- * _e is kept high apart from calling clock
- * _rw is kept 0 (write) apart from actions that uyse it differently
- *  -> on this program, the _rw is not used ... ym1784
- * _rs is set by the data/command writes
- */
-
-TextLCD_20X4::TextLCD_20X4(PinName rs, PinName e, PinName d0, PinName d1,
-    PinName d2, PinName d3, int columns, int rows) : _rs(rs), _e(e), _d(d0, d1, d2, d3),
-    _columns(columns), _rows(rows) {
-
-    _rows = 4;
-    _columns = 20;
-    // Mon, 27 Apr 2009 23:32:34 +0200
-    // Kevin Konradt:
-    // When using a LCD with 1 row x 16 characters
-    // instead of 2x16, try changing _columns to 8.
-    // (display seems to split the 16 characters into 
-    // 2 virtual rows with 8 characters each.)
-    //
-    // 2010/05/14 ym1784
-    // This program is only for 4 rows x 20 characters specific
-
-//  _rw = 0; // on this program, the _rw is not used ... ym1784
-    _e  = 1;
-    _rs = 0; // command mode
-
-    // Should theoretically wait 15ms, but most things will be powered up pre-reset
-    // so i'll disable that for the minute. If implemented, could wait 15ms post reset
-    // instead
-    wait(0.015); // for safety ... ym1784
-        
-    // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
-    for(int i=0; i<3; i++) {
-        writeNibble(0x3);
-        wait(0.00164);  // this command takes 1.64ms, so wait for it
-    }
-    writeNibble(0x2);   // 4-bit mode
-
-    writeCommand(0x28); // Function set 001 BW N F - -
-    writeCommand(0x0C);
-    writeCommand(0x6);  // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
-
-    cls();
-}
-
-int TextLCD_20X4::_putc(int value) {
-    if(value == '\n') {
-        newline();
-    } else {
-        writeData(value);
-    }
-    return value;
-}
-
-int TextLCD_20X4::_getc() {
-    return 0;
-}
-
-void TextLCD_20X4::newline() {
-    _column = 0;
-    _row++;
-    if(_row >= _rows) {
-        _row = 0;
-    }
-    locate(_column, _row);
-}
-
-void TextLCD_20X4::locate(int column, int row) {
-    if(column < 0 || column >= _columns || row < 0 || row >= _rows) {
-        error("locate(%d,%d) out of range on %dx%d display", column, row, _columns, _rows);
-        return;
-    }
-    _row = row;
-    _column = column;
-// modified for 20X4 LCD
-    switch (_row) {
-        case (0) : address = 0x80 + _column;
-        break;
-        case (1) : address = 0xc0 + _column;
-        break;
-        case (2) : address = 0x94 + _column;
-        break;
-        case (3) : address = 0xd4 + _column;
-        break;
-        } // switch
-    writeCommand(address);
-}
-
-void TextLCD_20X4::cls() {
-    writeCommand(0x01); // Clear Display
-    wait(0.00164f);     // This command takes 1.64 ms
-//    locate(0, 0);     // We don't have to do this here
-}
-
-void TextLCD_20X4::reset() {
-    cls();
-}
-
-void TextLCD_20X4::clock() {
-    wait(0.000040f);
-    _e = 0;
-    wait(0.000040f);  // most instructions take 40us
-    _e = 1;
-}
-
-void TextLCD_20X4::writeNibble(int value) {
-    _d = value;
-    clock();
-}
-
-void TextLCD_20X4::writeByte(int value) {
-    writeNibble(value >> 4);
-    writeNibble(value >> 0);
-}
-
-void TextLCD_20X4::writeCommand(int command) {
-    _rs = 0;
-    writeByte(command);
-}
-
-void TextLCD_20X4::writeData(int data) {
-    _rs = 1;
-    writeByte(data);
-    _column++;
-    if(_column >= _columns) {
-        newline();
-    }
-}