Mathew Swabey / LCDdisplay2

Updated

Dependents:   PROJECTTEST

TextLCD.cpp@0:e400f2ebb772, 2019-01-05 (annotated)

Committer:
Swabey89
Date:
Sat Jan 05 15:02:52 2019 +0000
Revision:
0:e400f2ebb772
Updated

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Swabey89 0:e400f2ebb772 1 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
Swabey89 0:e400f2ebb772 2 * Copyright (c) 2007-2010, sford, http://mbed.org
Swabey89 0:e400f2ebb772 3 *
Swabey89 0:e400f2ebb772 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
Swabey89 0:e400f2ebb772 5 * of this software and associated documentation files (the "Software"), to deal
Swabey89 0:e400f2ebb772 6 * in the Software without restriction, including without limitation the rights
Swabey89 0:e400f2ebb772 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
Swabey89 0:e400f2ebb772 8 * copies of the Software, and to permit persons to whom the Software is
Swabey89 0:e400f2ebb772 9 * furnished to do so, subject to the following conditions:
Swabey89 0:e400f2ebb772 10 *
Swabey89 0:e400f2ebb772 11 * The above copyright notice and this permission notice shall be included in
Swabey89 0:e400f2ebb772 12 * all copies or substantial portions of the Software.
Swabey89 0:e400f2ebb772 13 *
Swabey89 0:e400f2ebb772 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Swabey89 0:e400f2ebb772 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Swabey89 0:e400f2ebb772 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
Swabey89 0:e400f2ebb772 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Swabey89 0:e400f2ebb772 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Swabey89 0:e400f2ebb772 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
Swabey89 0:e400f2ebb772 20 * THE SOFTWARE.
Swabey89 0:e400f2ebb772 21 */
Swabey89 0:e400f2ebb772 22
Swabey89 0:e400f2ebb772 23 #include "TextLCD.h"
Swabey89 0:e400f2ebb772 24 #include "mbed.h"
Swabey89 0:e400f2ebb772 25
Swabey89 0:e400f2ebb772 26 TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
Swabey89 0:e400f2ebb772 27 PinName d6, PinName d7, LCDType type) : _rs(rs),
Swabey89 0:e400f2ebb772 28 _e(e), _d(d4, d5, d6, d7),
Swabey89 0:e400f2ebb772 29 _type(type) {
Swabey89 0:e400f2ebb772 30
Swabey89 0:e400f2ebb772 31 _e = 1;
Swabey89 0:e400f2ebb772 32 _rs = 0; // command mode
Swabey89 0:e400f2ebb772 33
Swabey89 0:e400f2ebb772 34 wait(0.015); // Wait 15ms to ensure powered up
Swabey89 0:e400f2ebb772 35
Swabey89 0:e400f2ebb772 36 // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
Swabey89 0:e400f2ebb772 37 for (int i=0; i<3; i++) {
Swabey89 0:e400f2ebb772 38 writeByte(0x3);
Swabey89 0:e400f2ebb772 39 wait(0.00164); // this command takes 1.64ms, so wait for it
Swabey89 0:e400f2ebb772 40 }
Swabey89 0:e400f2ebb772 41 writeByte(0x2); // 4-bit mode
Swabey89 0:e400f2ebb772 42 wait(0.000040f); // most instructions take 40us
Swabey89 0:e400f2ebb772 43
Swabey89 0:e400f2ebb772 44 writeCommand(0x28); // Function set 001 BW N F - -
Swabey89 0:e400f2ebb772 45 writeCommand(0x0C);
Swabey89 0:e400f2ebb772 46 writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
Swabey89 0:e400f2ebb772 47 cls();
Swabey89 0:e400f2ebb772 48 }
Swabey89 0:e400f2ebb772 49
Swabey89 0:e400f2ebb772 50 void TextLCD::character(int column, int row, int c) {
Swabey89 0:e400f2ebb772 51 int a = address(column, row);
Swabey89 0:e400f2ebb772 52 writeCommand(a);
Swabey89 0:e400f2ebb772 53 writeData(c);
Swabey89 0:e400f2ebb772 54 }
Swabey89 0:e400f2ebb772 55
Swabey89 0:e400f2ebb772 56 void TextLCD::cls() {
Swabey89 0:e400f2ebb772 57 writeCommand(0x01); // cls, and set cursor to 0
Swabey89 0:e400f2ebb772 58 wait(0.00164f); // This command takes 1.64 ms
Swabey89 0:e400f2ebb772 59 locate(0, 0);
Swabey89 0:e400f2ebb772 60 }
Swabey89 0:e400f2ebb772 61
Swabey89 0:e400f2ebb772 62 void TextLCD::locate(int column, int row) {
Swabey89 0:e400f2ebb772 63 _column = column;
Swabey89 0:e400f2ebb772 64 _row = row;
Swabey89 0:e400f2ebb772 65 }
Swabey89 0:e400f2ebb772 66
Swabey89 0:e400f2ebb772 67 int TextLCD::_putc(int value) {
Swabey89 0:e400f2ebb772 68 if (value == '\n') {
Swabey89 0:e400f2ebb772 69 _column = 0;
Swabey89 0:e400f2ebb772 70 _row++;
Swabey89 0:e400f2ebb772 71 if (_row >= rows()) {
Swabey89 0:e400f2ebb772 72 _row = 0;
Swabey89 0:e400f2ebb772 73 }
Swabey89 0:e400f2ebb772 74 } else {
Swabey89 0:e400f2ebb772 75 character(_column, _row, value);
Swabey89 0:e400f2ebb772 76 _column++;
Swabey89 0:e400f2ebb772 77 if (_column >= columns()) {
Swabey89 0:e400f2ebb772 78 _column = 0;
Swabey89 0:e400f2ebb772 79 _row++;
Swabey89 0:e400f2ebb772 80 if (_row >= rows()) {
Swabey89 0:e400f2ebb772 81 _row = 0;
Swabey89 0:e400f2ebb772 82 }
Swabey89 0:e400f2ebb772 83 }
Swabey89 0:e400f2ebb772 84 }
Swabey89 0:e400f2ebb772 85 return value;
Swabey89 0:e400f2ebb772 86 }
Swabey89 0:e400f2ebb772 87
Swabey89 0:e400f2ebb772 88 int TextLCD::_getc() {
Swabey89 0:e400f2ebb772 89 return -1;
Swabey89 0:e400f2ebb772 90 }
Swabey89 0:e400f2ebb772 91
Swabey89 0:e400f2ebb772 92 void TextLCD::writeByte(int value) {
Swabey89 0:e400f2ebb772 93 _d = value >> 4;
Swabey89 0:e400f2ebb772 94 wait(0.000040f); // most instructions take 40us
Swabey89 0:e400f2ebb772 95 _e = 0;
Swabey89 0:e400f2ebb772 96 wait(0.000040f);
Swabey89 0:e400f2ebb772 97 _e = 1;
Swabey89 0:e400f2ebb772 98 _d = value >> 0;
Swabey89 0:e400f2ebb772 99 wait(0.000040f);
Swabey89 0:e400f2ebb772 100 _e = 0;
Swabey89 0:e400f2ebb772 101 wait(0.000040f); // most instructions take 40us
Swabey89 0:e400f2ebb772 102 _e = 1;
Swabey89 0:e400f2ebb772 103 }
Swabey89 0:e400f2ebb772 104
Swabey89 0:e400f2ebb772 105 void TextLCD::writeCommand(int command) {
Swabey89 0:e400f2ebb772 106 _rs = 0;
Swabey89 0:e400f2ebb772 107 writeByte(command);
Swabey89 0:e400f2ebb772 108 }
Swabey89 0:e400f2ebb772 109
Swabey89 0:e400f2ebb772 110 void TextLCD::writeData(int data) {
Swabey89 0:e400f2ebb772 111 _rs = 1;
Swabey89 0:e400f2ebb772 112 writeByte(data);
Swabey89 0:e400f2ebb772 113 }
Swabey89 0:e400f2ebb772 114
Swabey89 0:e400f2ebb772 115 int TextLCD::address(int column, int row) {
Swabey89 0:e400f2ebb772 116 switch (_type) {
Swabey89 0:e400f2ebb772 117 case LCD20x4:
Swabey89 0:e400f2ebb772 118 switch (row) {
Swabey89 0:e400f2ebb772 119 case 0:
Swabey89 0:e400f2ebb772 120 return 0x80 + column;
Swabey89 0:e400f2ebb772 121 case 1:
Swabey89 0:e400f2ebb772 122 return 0xc0 + column;
Swabey89 0:e400f2ebb772 123 case 2:
Swabey89 0:e400f2ebb772 124 return 0x94 + column;
Swabey89 0:e400f2ebb772 125 case 3:
Swabey89 0:e400f2ebb772 126 return 0xd4 + column;
Swabey89 0:e400f2ebb772 127 }
Swabey89 0:e400f2ebb772 128 case LCD16x2B:
Swabey89 0:e400f2ebb772 129 return 0x80 + (row * 40) + column;
Swabey89 0:e400f2ebb772 130 case LCD16x2:
Swabey89 0:e400f2ebb772 131 case LCD20x2:
Swabey89 0:e400f2ebb772 132 default:
Swabey89 0:e400f2ebb772 133 return 0x80 + (row * 0x40) + column;
Swabey89 0:e400f2ebb772 134 }
Swabey89 0:e400f2ebb772 135 }
Swabey89 0:e400f2ebb772 136
Swabey89 0:e400f2ebb772 137 int TextLCD::columns() {
Swabey89 0:e400f2ebb772 138 switch (_type) {
Swabey89 0:e400f2ebb772 139 case LCD20x4:
Swabey89 0:e400f2ebb772 140 case LCD20x2:
Swabey89 0:e400f2ebb772 141 return 20;
Swabey89 0:e400f2ebb772 142 case LCD16x2:
Swabey89 0:e400f2ebb772 143 case LCD16x2B:
Swabey89 0:e400f2ebb772 144 default:
Swabey89 0:e400f2ebb772 145 return 16;
Swabey89 0:e400f2ebb772 146 }
Swabey89 0:e400f2ebb772 147 }
Swabey89 0:e400f2ebb772 148
Swabey89 0:e400f2ebb772 149 int TextLCD::rows() {
Swabey89 0:e400f2ebb772 150 switch (_type) {
Swabey89 0:e400f2ebb772 151 case LCD20x4:
Swabey89 0:e400f2ebb772 152 return 4;
Swabey89 0:e400f2ebb772 153 case LCD16x2:
Swabey89 0:e400f2ebb772 154 case LCD16x2B:
Swabey89 0:e400f2ebb772 155 case LCD20x2:
Swabey89 0:e400f2ebb772 156 default:
Swabey89 0:e400f2ebb772 157 return 2;
Swabey89 0:e400f2ebb772 158 }
Swabey89 0:e400f2ebb772 159 }