ze chen / TextLCD

hw

Dependents:   wave_player_mp3

TextLCD.cpp@0:d45fa961da1b, 2013-07-14 (annotated)

Committer:
zchen311
Date:
Sun Jul 14 20:29:29 2013 +0000
Revision:
0:d45fa961da1b
done

Who changed what in which revision?

UserRevisionLine numberNew contents of line
zchen311 0:d45fa961da1b 1 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
zchen311 0:d45fa961da1b 2 * Copyright (c) 2007-2010, sford, http://mbed.org
zchen311 0:d45fa961da1b 3 *
zchen311 0:d45fa961da1b 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
zchen311 0:d45fa961da1b 5 * of this software and associated documentation files (the "Software"), to deal
zchen311 0:d45fa961da1b 6 * in the Software without restriction, including without limitation the rights
zchen311 0:d45fa961da1b 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
zchen311 0:d45fa961da1b 8 * copies of the Software, and to permit persons to whom the Software is
zchen311 0:d45fa961da1b 9 * furnished to do so, subject to the following conditions:
zchen311 0:d45fa961da1b 10 *
zchen311 0:d45fa961da1b 11 * The above copyright notice and this permission notice shall be included in
zchen311 0:d45fa961da1b 12 * all copies or substantial portions of the Software.
zchen311 0:d45fa961da1b 13 *
zchen311 0:d45fa961da1b 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
zchen311 0:d45fa961da1b 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
zchen311 0:d45fa961da1b 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
zchen311 0:d45fa961da1b 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
zchen311 0:d45fa961da1b 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
zchen311 0:d45fa961da1b 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
zchen311 0:d45fa961da1b 20 * THE SOFTWARE.
zchen311 0:d45fa961da1b 21 */
zchen311 0:d45fa961da1b 22
zchen311 0:d45fa961da1b 23 #include "TextLCD.h"
zchen311 0:d45fa961da1b 24 #include "mbed.h"
zchen311 0:d45fa961da1b 25
zchen311 0:d45fa961da1b 26 TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
zchen311 0:d45fa961da1b 27 PinName d6, PinName d7, LCDType type) : _rs(rs),
zchen311 0:d45fa961da1b 28 _e(e), _d(d4, d5, d6, d7),
zchen311 0:d45fa961da1b 29 _type(type) {
zchen311 0:d45fa961da1b 30
zchen311 0:d45fa961da1b 31 _e = 1;
zchen311 0:d45fa961da1b 32 _rs = 0; // command mode
zchen311 0:d45fa961da1b 33
zchen311 0:d45fa961da1b 34 wait(0.015); // Wait 15ms to ensure powered up
zchen311 0:d45fa961da1b 35
zchen311 0:d45fa961da1b 36 // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
zchen311 0:d45fa961da1b 37 for (int i=0; i<3; i++) {
zchen311 0:d45fa961da1b 38 writeByte(0x3);
zchen311 0:d45fa961da1b 39 wait(0.00164); // this command takes 1.64ms, so wait for it
zchen311 0:d45fa961da1b 40 }
zchen311 0:d45fa961da1b 41 writeByte(0x2); // 4-bit mode
zchen311 0:d45fa961da1b 42 wait(0.000040f); // most instructions take 40us
zchen311 0:d45fa961da1b 43
zchen311 0:d45fa961da1b 44 writeCommand(0x28); // Function set 001 BW N F - -
zchen311 0:d45fa961da1b 45 writeCommand(0x0C);
zchen311 0:d45fa961da1b 46 writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
zchen311 0:d45fa961da1b 47 cls();
zchen311 0:d45fa961da1b 48 }
zchen311 0:d45fa961da1b 49
zchen311 0:d45fa961da1b 50 void TextLCD::character(int column, int row, int c) {
zchen311 0:d45fa961da1b 51 int a = address(column, row);
zchen311 0:d45fa961da1b 52 writeCommand(a);
zchen311 0:d45fa961da1b 53 writeData(c);
zchen311 0:d45fa961da1b 54 }
zchen311 0:d45fa961da1b 55
zchen311 0:d45fa961da1b 56 void TextLCD::cls() {
zchen311 0:d45fa961da1b 57 writeCommand(0x01); // cls, and set cursor to 0
zchen311 0:d45fa961da1b 58 wait(0.00164f); // This command takes 1.64 ms
zchen311 0:d45fa961da1b 59 locate(0, 0);
zchen311 0:d45fa961da1b 60 }
zchen311 0:d45fa961da1b 61
zchen311 0:d45fa961da1b 62 void TextLCD::locate(int column, int row) {
zchen311 0:d45fa961da1b 63 _column = column;
zchen311 0:d45fa961da1b 64 _row = row;
zchen311 0:d45fa961da1b 65 }
zchen311 0:d45fa961da1b 66
zchen311 0:d45fa961da1b 67 int TextLCD::_putc(int value) {
zchen311 0:d45fa961da1b 68 if (value == '\n') {
zchen311 0:d45fa961da1b 69 _column = 0;
zchen311 0:d45fa961da1b 70 _row++;
zchen311 0:d45fa961da1b 71 if (_row >= rows()) {
zchen311 0:d45fa961da1b 72 _row = 0;
zchen311 0:d45fa961da1b 73 }
zchen311 0:d45fa961da1b 74 } else {
zchen311 0:d45fa961da1b 75 character(_column, _row, value);
zchen311 0:d45fa961da1b 76 _column++;
zchen311 0:d45fa961da1b 77 if (_column >= columns()) {
zchen311 0:d45fa961da1b 78 _column = 0;
zchen311 0:d45fa961da1b 79 _row++;
zchen311 0:d45fa961da1b 80 if (_row >= rows()) {
zchen311 0:d45fa961da1b 81 _row = 0;
zchen311 0:d45fa961da1b 82 }
zchen311 0:d45fa961da1b 83 }
zchen311 0:d45fa961da1b 84 }
zchen311 0:d45fa961da1b 85 return value;
zchen311 0:d45fa961da1b 86 }
zchen311 0:d45fa961da1b 87
zchen311 0:d45fa961da1b 88 int TextLCD::_getc() {
zchen311 0:d45fa961da1b 89 return -1;
zchen311 0:d45fa961da1b 90 }
zchen311 0:d45fa961da1b 91
zchen311 0:d45fa961da1b 92 void TextLCD::writeByte(int value) {
zchen311 0:d45fa961da1b 93 _d = value >> 4;
zchen311 0:d45fa961da1b 94 wait(0.000040f); // most instructions take 40us
zchen311 0:d45fa961da1b 95 _e = 0;
zchen311 0:d45fa961da1b 96 wait(0.000040f);
zchen311 0:d45fa961da1b 97 _e = 1;
zchen311 0:d45fa961da1b 98 _d = value >> 0;
zchen311 0:d45fa961da1b 99 wait(0.000040f);
zchen311 0:d45fa961da1b 100 _e = 0;
zchen311 0:d45fa961da1b 101 wait(0.000040f); // most instructions take 40us
zchen311 0:d45fa961da1b 102 _e = 1;
zchen311 0:d45fa961da1b 103 }
zchen311 0:d45fa961da1b 104
zchen311 0:d45fa961da1b 105 void TextLCD::writeCommand(int command) {
zchen311 0:d45fa961da1b 106 _rs = 0;
zchen311 0:d45fa961da1b 107 writeByte(command);
zchen311 0:d45fa961da1b 108 }
zchen311 0:d45fa961da1b 109
zchen311 0:d45fa961da1b 110 void TextLCD::writeData(int data) {
zchen311 0:d45fa961da1b 111 _rs = 1;
zchen311 0:d45fa961da1b 112 writeByte(data);
zchen311 0:d45fa961da1b 113 }
zchen311 0:d45fa961da1b 114
zchen311 0:d45fa961da1b 115 int TextLCD::address(int column, int row) {
zchen311 0:d45fa961da1b 116 switch (_type) {
zchen311 0:d45fa961da1b 117 case LCD20x4:
zchen311 0:d45fa961da1b 118 switch (row) {
zchen311 0:d45fa961da1b 119 case 0:
zchen311 0:d45fa961da1b 120 return 0x80 + column;
zchen311 0:d45fa961da1b 121 case 1:
zchen311 0:d45fa961da1b 122 return 0xc0 + column;
zchen311 0:d45fa961da1b 123 case 2:
zchen311 0:d45fa961da1b 124 return 0x94 + column;
zchen311 0:d45fa961da1b 125 case 3:
zchen311 0:d45fa961da1b 126 return 0xd4 + column;
zchen311 0:d45fa961da1b 127 }
zchen311 0:d45fa961da1b 128 case LCD16x2B:
zchen311 0:d45fa961da1b 129 return 0x80 + (row * 40) + column;
zchen311 0:d45fa961da1b 130 case LCD16x2:
zchen311 0:d45fa961da1b 131 case LCD20x2:
zchen311 0:d45fa961da1b 132 default:
zchen311 0:d45fa961da1b 133 return 0x80 + (row * 0x40) + column;
zchen311 0:d45fa961da1b 134 }
zchen311 0:d45fa961da1b 135 }
zchen311 0:d45fa961da1b 136
zchen311 0:d45fa961da1b 137 int TextLCD::columns() {
zchen311 0:d45fa961da1b 138 switch (_type) {
zchen311 0:d45fa961da1b 139 case LCD20x4:
zchen311 0:d45fa961da1b 140 case LCD20x2:
zchen311 0:d45fa961da1b 141 return 20;
zchen311 0:d45fa961da1b 142 case LCD16x2:
zchen311 0:d45fa961da1b 143 case LCD16x2B:
zchen311 0:d45fa961da1b 144 default:
zchen311 0:d45fa961da1b 145 return 16;
zchen311 0:d45fa961da1b 146 }
zchen311 0:d45fa961da1b 147 }
zchen311 0:d45fa961da1b 148
zchen311 0:d45fa961da1b 149 int TextLCD::rows() {
zchen311 0:d45fa961da1b 150 switch (_type) {
zchen311 0:d45fa961da1b 151 case LCD20x4:
zchen311 0:d45fa961da1b 152 return 4;
zchen311 0:d45fa961da1b 153 case LCD16x2:
zchen311 0:d45fa961da1b 154 case LCD16x2B:
zchen311 0:d45fa961da1b 155 case LCD20x2:
zchen311 0:d45fa961da1b 156 default:
zchen311 0:d45fa961da1b 157 return 2;
zchen311 0:d45fa961da1b 158 }
zchen311 0:d45fa961da1b 159 }