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TextLCD/TextLCD.cpp@0:ed9c40a5ca0d, 2017-09-28 (annotated)

Committer:
SMART_CLEO
Date:
Thu Sep 28 03:29:14 2017 +0000
Revision:
0:ed9c40a5ca0d
SMART_CLEO

Who changed what in which revision?

UserRevisionLine numberNew contents of line
SMART_CLEO 0:ed9c40a5ca0d 1 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
SMART_CLEO 0:ed9c40a5ca0d 2 * Copyright (c) 2007-2010, sford
SMART_CLEO 0:ed9c40a5ca0d 3 *
SMART_CLEO 0:ed9c40a5ca0d 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
SMART_CLEO 0:ed9c40a5ca0d 5 * of this software and associated documentation files (the "Software"), to deal
SMART_CLEO 0:ed9c40a5ca0d 6 * in the Software without restriction, including without limitation the rights
SMART_CLEO 0:ed9c40a5ca0d 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
SMART_CLEO 0:ed9c40a5ca0d 8 * copies of the Software, and to permit persons to whom the Software is
SMART_CLEO 0:ed9c40a5ca0d 9 * furnished to do so, subject to the following conditions:
SMART_CLEO 0:ed9c40a5ca0d 10 *
SMART_CLEO 0:ed9c40a5ca0d 11 * The above copyright notice and this permission notice shall be included in
SMART_CLEO 0:ed9c40a5ca0d 12 * all copies or substantial portions of the Software.
SMART_CLEO 0:ed9c40a5ca0d 13 *
SMART_CLEO 0:ed9c40a5ca0d 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
SMART_CLEO 0:ed9c40a5ca0d 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
SMART_CLEO 0:ed9c40a5ca0d 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
SMART_CLEO 0:ed9c40a5ca0d 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
SMART_CLEO 0:ed9c40a5ca0d 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
SMART_CLEO 0:ed9c40a5ca0d 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
SMART_CLEO 0:ed9c40a5ca0d 20 * THE SOFTWARE.
SMART_CLEO 0:ed9c40a5ca0d 21 */
SMART_CLEO 0:ed9c40a5ca0d 22
SMART_CLEO 0:ed9c40a5ca0d 23 #include "TextLCD.h"
SMART_CLEO 0:ed9c40a5ca0d 24 #include "mbed.h"
SMART_CLEO 0:ed9c40a5ca0d 25
SMART_CLEO 0:ed9c40a5ca0d 26 TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1,
SMART_CLEO 0:ed9c40a5ca0d 27 PinName d2, PinName d3, LCDType type) : _rs(rs), _rw(rw),
SMART_CLEO 0:ed9c40a5ca0d 28 _e(e), _d(d0, d1, d2, d3),
SMART_CLEO 0:ed9c40a5ca0d 29 _type(type) {
SMART_CLEO 0:ed9c40a5ca0d 30
SMART_CLEO 0:ed9c40a5ca0d 31 _rw = 0;
SMART_CLEO 0:ed9c40a5ca0d 32 _e = 1;
SMART_CLEO 0:ed9c40a5ca0d 33 _rs = 0; // command mode
SMART_CLEO 0:ed9c40a5ca0d 34 _d.output();
SMART_CLEO 0:ed9c40a5ca0d 35
SMART_CLEO 0:ed9c40a5ca0d 36 wait(0.015); // Wait 15ms to ensure powered up
SMART_CLEO 0:ed9c40a5ca0d 37
SMART_CLEO 0:ed9c40a5ca0d 38 // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
SMART_CLEO 0:ed9c40a5ca0d 39 for (int i=0; i<3; i++) {
SMART_CLEO 0:ed9c40a5ca0d 40 writeByte(0x3);
SMART_CLEO 0:ed9c40a5ca0d 41 wait(0.00164); // this command takes 1.64ms, so wait for it
SMART_CLEO 0:ed9c40a5ca0d 42 }
SMART_CLEO 0:ed9c40a5ca0d 43 writeByte(0x2); // 4-bit mode
SMART_CLEO 0:ed9c40a5ca0d 44 wait(0.000040f); // most instructions take 40us
SMART_CLEO 0:ed9c40a5ca0d 45
SMART_CLEO 0:ed9c40a5ca0d 46 writeCommand(0x28); // Function set 001 BW N F - -
SMART_CLEO 0:ed9c40a5ca0d 47 writeCommand(0x0C);
SMART_CLEO 0:ed9c40a5ca0d 48 writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
SMART_CLEO 0:ed9c40a5ca0d 49 cls();
SMART_CLEO 0:ed9c40a5ca0d 50 }
SMART_CLEO 0:ed9c40a5ca0d 51
SMART_CLEO 0:ed9c40a5ca0d 52 void TextLCD::character(int column, int row, int c) {
SMART_CLEO 0:ed9c40a5ca0d 53 int a = address(column, row);
SMART_CLEO 0:ed9c40a5ca0d 54 writeCommand(a);
SMART_CLEO 0:ed9c40a5ca0d 55 writeData(c);
SMART_CLEO 0:ed9c40a5ca0d 56 }
SMART_CLEO 0:ed9c40a5ca0d 57
SMART_CLEO 0:ed9c40a5ca0d 58 void TextLCD::cls() {
SMART_CLEO 0:ed9c40a5ca0d 59 writeCommand(0x01); // cls, and set cursor to 0
SMART_CLEO 0:ed9c40a5ca0d 60 wait(0.00164f); // This command takes 1.64 ms
SMART_CLEO 0:ed9c40a5ca0d 61 locate(0, 0);
SMART_CLEO 0:ed9c40a5ca0d 62 }
SMART_CLEO 0:ed9c40a5ca0d 63
SMART_CLEO 0:ed9c40a5ca0d 64 void TextLCD::locate(int column, int row) {
SMART_CLEO 0:ed9c40a5ca0d 65 _column = column;
SMART_CLEO 0:ed9c40a5ca0d 66 _row = row;
SMART_CLEO 0:ed9c40a5ca0d 67 }
SMART_CLEO 0:ed9c40a5ca0d 68
SMART_CLEO 0:ed9c40a5ca0d 69 int TextLCD::_putc(int value) {
SMART_CLEO 0:ed9c40a5ca0d 70 if (value == '\n') {
SMART_CLEO 0:ed9c40a5ca0d 71 _column = 0;
SMART_CLEO 0:ed9c40a5ca0d 72 _row++;
SMART_CLEO 0:ed9c40a5ca0d 73 if (_row >= rows()) {
SMART_CLEO 0:ed9c40a5ca0d 74 _row = 0;
SMART_CLEO 0:ed9c40a5ca0d 75 }
SMART_CLEO 0:ed9c40a5ca0d 76 } else {
SMART_CLEO 0:ed9c40a5ca0d 77 character(_column, _row, value);
SMART_CLEO 0:ed9c40a5ca0d 78 _column++;
SMART_CLEO 0:ed9c40a5ca0d 79 if (_column >= columns()) {
SMART_CLEO 0:ed9c40a5ca0d 80 _column = 0;
SMART_CLEO 0:ed9c40a5ca0d 81 _row++;
SMART_CLEO 0:ed9c40a5ca0d 82 if (_row >= rows()) {
SMART_CLEO 0:ed9c40a5ca0d 83 _row = 0;
SMART_CLEO 0:ed9c40a5ca0d 84 }
SMART_CLEO 0:ed9c40a5ca0d 85 }
SMART_CLEO 0:ed9c40a5ca0d 86 }
SMART_CLEO 0:ed9c40a5ca0d 87 return value;
SMART_CLEO 0:ed9c40a5ca0d 88 }
SMART_CLEO 0:ed9c40a5ca0d 89
SMART_CLEO 0:ed9c40a5ca0d 90 int TextLCD::_getc() {
SMART_CLEO 0:ed9c40a5ca0d 91 return -1;
SMART_CLEO 0:ed9c40a5ca0d 92 }
SMART_CLEO 0:ed9c40a5ca0d 93
SMART_CLEO 0:ed9c40a5ca0d 94 void TextLCD::writeByte(int value) {
SMART_CLEO 0:ed9c40a5ca0d 95 _rw = 0;
SMART_CLEO 0:ed9c40a5ca0d 96
SMART_CLEO 0:ed9c40a5ca0d 97 _d = value >> 4;
SMART_CLEO 0:ed9c40a5ca0d 98 wait(0.000040f); // most instructions take 40us
SMART_CLEO 0:ed9c40a5ca0d 99 _e = 0;
SMART_CLEO 0:ed9c40a5ca0d 100 wait(0.000040f);
SMART_CLEO 0:ed9c40a5ca0d 101 _e = 1;
SMART_CLEO 0:ed9c40a5ca0d 102 _d = value >> 0;
SMART_CLEO 0:ed9c40a5ca0d 103 wait(0.000040f);
SMART_CLEO 0:ed9c40a5ca0d 104 _e = 0;
SMART_CLEO 0:ed9c40a5ca0d 105 wait(0.000040f); // most instructions take 40us
SMART_CLEO 0:ed9c40a5ca0d 106 _e = 1;
SMART_CLEO 0:ed9c40a5ca0d 107 }
SMART_CLEO 0:ed9c40a5ca0d 108
SMART_CLEO 0:ed9c40a5ca0d 109 void TextLCD::writeCommand(int command) {
SMART_CLEO 0:ed9c40a5ca0d 110 _rs = 0;
SMART_CLEO 0:ed9c40a5ca0d 111 writeByte(command);
SMART_CLEO 0:ed9c40a5ca0d 112 }
SMART_CLEO 0:ed9c40a5ca0d 113
SMART_CLEO 0:ed9c40a5ca0d 114 void TextLCD::writeData(int data) {
SMART_CLEO 0:ed9c40a5ca0d 115 _rs = 1;
SMART_CLEO 0:ed9c40a5ca0d 116 writeByte(data);
SMART_CLEO 0:ed9c40a5ca0d 117 }
SMART_CLEO 0:ed9c40a5ca0d 118
SMART_CLEO 0:ed9c40a5ca0d 119 int TextLCD::address(int column, int row) {
SMART_CLEO 0:ed9c40a5ca0d 120 switch (_type) {
SMART_CLEO 0:ed9c40a5ca0d 121 case LCD20x4:
SMART_CLEO 0:ed9c40a5ca0d 122 switch (row) {
SMART_CLEO 0:ed9c40a5ca0d 123 case 0:
SMART_CLEO 0:ed9c40a5ca0d 124 return 0x80 + column;
SMART_CLEO 0:ed9c40a5ca0d 125 case 1:
SMART_CLEO 0:ed9c40a5ca0d 126 return 0xc0 + column;
SMART_CLEO 0:ed9c40a5ca0d 127 case 2:
SMART_CLEO 0:ed9c40a5ca0d 128 return 0x94 + column;
SMART_CLEO 0:ed9c40a5ca0d 129 case 3:
SMART_CLEO 0:ed9c40a5ca0d 130 return 0xd4 + column;
SMART_CLEO 0:ed9c40a5ca0d 131 }
SMART_CLEO 0:ed9c40a5ca0d 132 case LCD16x2B:
SMART_CLEO 0:ed9c40a5ca0d 133 return 0x80 + (row * 40) + column;
SMART_CLEO 0:ed9c40a5ca0d 134 case LCD16x2:
SMART_CLEO 0:ed9c40a5ca0d 135 case LCD20x2:
SMART_CLEO 0:ed9c40a5ca0d 136 default:
SMART_CLEO 0:ed9c40a5ca0d 137 return 0x80 + (row * 0x40) + column;
SMART_CLEO 0:ed9c40a5ca0d 138 }
SMART_CLEO 0:ed9c40a5ca0d 139 }
SMART_CLEO 0:ed9c40a5ca0d 140
SMART_CLEO 0:ed9c40a5ca0d 141 int TextLCD::columns() {
SMART_CLEO 0:ed9c40a5ca0d 142 switch (_type) {
SMART_CLEO 0:ed9c40a5ca0d 143 case LCD20x4:
SMART_CLEO 0:ed9c40a5ca0d 144 case LCD20x2:
SMART_CLEO 0:ed9c40a5ca0d 145 return 20;
SMART_CLEO 0:ed9c40a5ca0d 146 case LCD16x2:
SMART_CLEO 0:ed9c40a5ca0d 147 case LCD16x2B:
SMART_CLEO 0:ed9c40a5ca0d 148 default:
SMART_CLEO 0:ed9c40a5ca0d 149 return 16;
SMART_CLEO 0:ed9c40a5ca0d 150 }
SMART_CLEO 0:ed9c40a5ca0d 151 }
SMART_CLEO 0:ed9c40a5ca0d 152
SMART_CLEO 0:ed9c40a5ca0d 153 int TextLCD::rows() {
SMART_CLEO 0:ed9c40a5ca0d 154 switch (_type) {
SMART_CLEO 0:ed9c40a5ca0d 155 case LCD20x4:
SMART_CLEO 0:ed9c40a5ca0d 156 return 4;
SMART_CLEO 0:ed9c40a5ca0d 157 case LCD16x2:
SMART_CLEO 0:ed9c40a5ca0d 158 case LCD16x2B:
SMART_CLEO 0:ed9c40a5ca0d 159 case LCD20x2:
SMART_CLEO 0:ed9c40a5ca0d 160 default:
SMART_CLEO 0:ed9c40a5ca0d 161 return 2;
SMART_CLEO 0:ed9c40a5ca0d 162 }
SMART_CLEO 0:ed9c40a5ca0d 163 }