Joachim Andersen / TextLCD

1

Dependents:   Program_R11

TextLCD.cpp@9:0893d986e717, 2013-01-31 (annotated)

Committer:
wim
Date:
Thu Jan 31 19:46:00 2013 +0000
Revision:
9:0893d986e717
Parent:
8:03116f75b66e
Child:
10:dd9b3a696acd
Tested on several LCD types

Who changed what in which revision?

UserRevisionLine numberNew contents of line
simon 1:ac48b187213c 1 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
simon 6:e4cb7ddee0d3 2 * Copyright (c) 2007-2010, sford, http://mbed.org
wim 8:03116f75b66e 3 * 2013, WH, Updated LCD types and fixed lcd address issues
simon 1:ac48b187213c 4 *
simon 1:ac48b187213c 5 * Permission is hereby granted, free of charge, to any person obtaining a copy
simon 1:ac48b187213c 6 * of this software and associated documentation files (the "Software"), to deal
simon 1:ac48b187213c 7 * in the Software without restriction, including without limitation the rights
simon 1:ac48b187213c 8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
simon 1:ac48b187213c 9 * copies of the Software, and to permit persons to whom the Software is
simon 1:ac48b187213c 10 * furnished to do so, subject to the following conditions:
simon 1:ac48b187213c 11 *
simon 1:ac48b187213c 12 * The above copyright notice and this permission notice shall be included in
simon 1:ac48b187213c 13 * all copies or substantial portions of the Software.
simon 1:ac48b187213c 14 *
simon 1:ac48b187213c 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
simon 1:ac48b187213c 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
simon 1:ac48b187213c 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
simon 1:ac48b187213c 18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
simon 1:ac48b187213c 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
simon 1:ac48b187213c 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
simon 1:ac48b187213c 21 * THE SOFTWARE.
simon 1:ac48b187213c 22 */
simon 1:ac48b187213c 23
simon 1:ac48b187213c 24 #include "TextLCD.h"
simon 1:ac48b187213c 25 #include "mbed.h"
simon 1:ac48b187213c 26
simon 7:44f34c09bd37 27 TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
simon 7:44f34c09bd37 28 PinName d6, PinName d7, LCDType type) : _rs(rs),
simon 7:44f34c09bd37 29 _e(e), _d(d4, d5, d6, d7),
simon 1:ac48b187213c 30 _type(type) {
simon 1:ac48b187213c 31
simon 1:ac48b187213c 32 _e = 1;
simon 1:ac48b187213c 33 _rs = 0; // command mode
simon 1:ac48b187213c 34
simon 1:ac48b187213c 35 wait(0.015); // Wait 15ms to ensure powered up
simon 1:ac48b187213c 36
simon 1:ac48b187213c 37 // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
simon 1:ac48b187213c 38 for (int i=0; i<3; i++) {
simon 1:ac48b187213c 39 writeByte(0x3);
simon 1:ac48b187213c 40 wait(0.00164); // this command takes 1.64ms, so wait for it
simon 1:ac48b187213c 41 }
simon 1:ac48b187213c 42 writeByte(0x2); // 4-bit mode
simon 1:ac48b187213c 43 wait(0.000040f); // most instructions take 40us
simon 1:ac48b187213c 44
simon 1:ac48b187213c 45 writeCommand(0x28); // Function set 001 BW N F - -
simon 1:ac48b187213c 46 writeCommand(0x0C);
wim 8:03116f75b66e 47 writeCommand(0x06); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
simon 1:ac48b187213c 48 cls();
simon 1:ac48b187213c 49 }
simon 1:ac48b187213c 50
wim 8:03116f75b66e 51
simon 1:ac48b187213c 52 void TextLCD::character(int column, int row, int c) {
wim 8:03116f75b66e 53 int addr = getAddress(column, row);
wim 8:03116f75b66e 54
wim 8:03116f75b66e 55 writeCommand(0x80 | addr);
simon 1:ac48b187213c 56 writeData(c);
simon 1:ac48b187213c 57 }
simon 1:ac48b187213c 58
wim 8:03116f75b66e 59
simon 1:ac48b187213c 60 void TextLCD::cls() {
simon 1:ac48b187213c 61 writeCommand(0x01); // cls, and set cursor to 0
simon 1:ac48b187213c 62 wait(0.00164f); // This command takes 1.64 ms
simon 1:ac48b187213c 63 locate(0, 0);
simon 1:ac48b187213c 64 }
simon 1:ac48b187213c 65
simon 1:ac48b187213c 66 void TextLCD::locate(int column, int row) {
simon 1:ac48b187213c 67 _column = column;
simon 1:ac48b187213c 68 _row = row;
simon 1:ac48b187213c 69 }
simon 1:ac48b187213c 70
simon 1:ac48b187213c 71 int TextLCD::_putc(int value) {
simon 1:ac48b187213c 72 if (value == '\n') {
simon 1:ac48b187213c 73 _column = 0;
simon 1:ac48b187213c 74 _row++;
simon 1:ac48b187213c 75 if (_row >= rows()) {
simon 1:ac48b187213c 76 _row = 0;
simon 1:ac48b187213c 77 }
simon 1:ac48b187213c 78 } else {
simon 1:ac48b187213c 79 character(_column, _row, value);
simon 1:ac48b187213c 80 _column++;
simon 1:ac48b187213c 81 if (_column >= columns()) {
simon 1:ac48b187213c 82 _column = 0;
simon 1:ac48b187213c 83 _row++;
simon 1:ac48b187213c 84 if (_row >= rows()) {
simon 1:ac48b187213c 85 _row = 0;
simon 1:ac48b187213c 86 }
simon 1:ac48b187213c 87 }
simon 1:ac48b187213c 88 }
simon 1:ac48b187213c 89 return value;
simon 1:ac48b187213c 90 }
simon 1:ac48b187213c 91
simon 1:ac48b187213c 92 int TextLCD::_getc() {
simon 1:ac48b187213c 93 return -1;
simon 1:ac48b187213c 94 }
simon 1:ac48b187213c 95
simon 1:ac48b187213c 96 void TextLCD::writeByte(int value) {
simon 1:ac48b187213c 97 _d = value >> 4;
simon 1:ac48b187213c 98 wait(0.000040f); // most instructions take 40us
simon 1:ac48b187213c 99 _e = 0;
simon 1:ac48b187213c 100 wait(0.000040f);
simon 1:ac48b187213c 101 _e = 1;
simon 1:ac48b187213c 102 _d = value >> 0;
simon 1:ac48b187213c 103 wait(0.000040f);
simon 1:ac48b187213c 104 _e = 0;
simon 1:ac48b187213c 105 wait(0.000040f); // most instructions take 40us
simon 1:ac48b187213c 106 _e = 1;
simon 1:ac48b187213c 107 }
simon 1:ac48b187213c 108
simon 1:ac48b187213c 109 void TextLCD::writeCommand(int command) {
simon 1:ac48b187213c 110 _rs = 0;
simon 1:ac48b187213c 111 writeByte(command);
simon 1:ac48b187213c 112 }
simon 1:ac48b187213c 113
simon 1:ac48b187213c 114 void TextLCD::writeData(int data) {
simon 1:ac48b187213c 115 _rs = 1;
simon 1:ac48b187213c 116 writeByte(data);
simon 1:ac48b187213c 117 }
simon 1:ac48b187213c 118
wim 8:03116f75b66e 119
wim 8:03116f75b66e 120 #if (0)
wim 8:03116f75b66e 121 // This is the original method.
wim 8:03116f75b66e 122 // It is confusing since it returns the memoryaddress or-ed with the set memorycommand 0x80.
wim 8:03116f75b66e 123 // Left it in here for compatibility with older code. New applications should use getAddress() instead.
wim 8:03116f75b66e 124 //
simon 1:ac48b187213c 125 int TextLCD::address(int column, int row) {
simon 1:ac48b187213c 126 switch (_type) {
simon 1:ac48b187213c 127 case LCD20x4:
simon 1:ac48b187213c 128 switch (row) {
simon 1:ac48b187213c 129 case 0:
simon 1:ac48b187213c 130 return 0x80 + column;
simon 1:ac48b187213c 131 case 1:
simon 1:ac48b187213c 132 return 0xc0 + column;
simon 1:ac48b187213c 133 case 2:
simon 1:ac48b187213c 134 return 0x94 + column;
simon 1:ac48b187213c 135 case 3:
simon 1:ac48b187213c 136 return 0xd4 + column;
simon 1:ac48b187213c 137 }
simon 1:ac48b187213c 138 case LCD16x2B:
simon 4:bf5b706f8d32 139 return 0x80 + (row * 40) + column;
simon 1:ac48b187213c 140 case LCD16x2:
simon 1:ac48b187213c 141 case LCD20x2:
simon 1:ac48b187213c 142 default:
simon 4:bf5b706f8d32 143 return 0x80 + (row * 0x40) + column;
simon 1:ac48b187213c 144 }
simon 1:ac48b187213c 145 }
wim 8:03116f75b66e 146 #endif
wim 8:03116f75b66e 147
wim 8:03116f75b66e 148
wim 8:03116f75b66e 149 // This replaces the original method.
wim 8:03116f75b66e 150 // Left it in here for compatibility with older code. New applications should use getAddress() instead.
wim 8:03116f75b66e 151 int TextLCD::address(int column, int row) {
wim 8:03116f75b66e 152 return 0x80 | getAddress(column, row);
wim 8:03116f75b66e 153 }
wim 8:03116f75b66e 154
wim 8:03116f75b66e 155 // This is new method to return the memory address based on row, column and displaytype.
wim 8:03116f75b66e 156 //
wim 8:03116f75b66e 157 int TextLCD::getAddress(int column, int row) {
wim 8:03116f75b66e 158
wim 8:03116f75b66e 159 switch (_type) {
wim 8:03116f75b66e 160 case LCD8x1:
wim 8:03116f75b66e 161 return 0x00 + column;
wim 8:03116f75b66e 162
wim 8:03116f75b66e 163 case LCD16x4:
wim 8:03116f75b66e 164 switch (row) {
wim 8:03116f75b66e 165 case 0:
wim 8:03116f75b66e 166 return 0x00 + column;
wim 8:03116f75b66e 167 case 1:
wim 8:03116f75b66e 168 return 0x40 + column;
wim 8:03116f75b66e 169 case 2:
wim 8:03116f75b66e 170 return 0x10 + column;
wim 8:03116f75b66e 171 case 3:
wim 8:03116f75b66e 172 return 0x50 + column;
wim 8:03116f75b66e 173 }
wim 8:03116f75b66e 174
wim 8:03116f75b66e 175 case LCD20x4:
wim 8:03116f75b66e 176 switch (row) {
wim 8:03116f75b66e 177 case 0:
wim 8:03116f75b66e 178 return 0x00 + column;
wim 8:03116f75b66e 179 case 1:
wim 8:03116f75b66e 180 return 0x40 + column;
wim 8:03116f75b66e 181 case 2:
wim 8:03116f75b66e 182 return 0x14 + column;
wim 8:03116f75b66e 183 case 3:
wim 8:03116f75b66e 184 return 0x54 + column;
wim 8:03116f75b66e 185 }
wim 8:03116f75b66e 186
wim 8:03116f75b66e 187 // Not sure about this one, seems wrong.
wim 8:03116f75b66e 188 case LCD16x2B:
wim 8:03116f75b66e 189 return 0x00 + (row * 40) + column;
wim 8:03116f75b66e 190
wim 8:03116f75b66e 191 case LCD8x2:
wim 8:03116f75b66e 192 case LCD16x2:
wim 8:03116f75b66e 193 case LCD20x2:
wim 8:03116f75b66e 194 case LCD24x2:
wim 9:0893d986e717 195 case LCD40x2:
wim 8:03116f75b66e 196 return 0x00 + (row * 0x40) + column;
wim 8:03116f75b66e 197
wim 8:03116f75b66e 198 // Should never get here.
wim 8:03116f75b66e 199 default:
wim 8:03116f75b66e 200 return 0x00;
wim 8:03116f75b66e 201 }
wim 8:03116f75b66e 202 }
wim 8:03116f75b66e 203
wim 8:03116f75b66e 204
wim 8:03116f75b66e 205 // Added for consistency. Set row, colum and update memoryaddress.
wim 8:03116f75b66e 206 //
wim 8:03116f75b66e 207 void TextLCD::setAddress(int column, int row) {
wim 8:03116f75b66e 208
wim 8:03116f75b66e 209 locate(column, row);
wim 8:03116f75b66e 210
wim 8:03116f75b66e 211 int addr = getAddress(column, row);
wim 8:03116f75b66e 212
wim 8:03116f75b66e 213 writeCommand(0x80 | addr);
wim 8:03116f75b66e 214 }
simon 1:ac48b187213c 215
simon 1:ac48b187213c 216 int TextLCD::columns() {
simon 1:ac48b187213c 217 switch (_type) {
wim 8:03116f75b66e 218 case LCD8x1:
wim 8:03116f75b66e 219 case LCD8x2:
wim 8:03116f75b66e 220 return 8;
wim 8:03116f75b66e 221
simon 1:ac48b187213c 222 case LCD16x2:
simon 1:ac48b187213c 223 case LCD16x2B:
wim 8:03116f75b66e 224 case LCD16x4:
wim 8:03116f75b66e 225 return 16;
wim 8:03116f75b66e 226
wim 8:03116f75b66e 227 case LCD20x2:
wim 8:03116f75b66e 228 case LCD20x4:
wim 8:03116f75b66e 229 return 20;
wim 8:03116f75b66e 230
wim 8:03116f75b66e 231 case LCD24x2:
wim 8:03116f75b66e 232 return 24;
wim 9:0893d986e717 233
wim 9:0893d986e717 234 case LCD40x2:
wim 9:0893d986e717 235 return 40;
wim 8:03116f75b66e 236
wim 8:03116f75b66e 237 // Should never get here.
simon 1:ac48b187213c 238 default:
wim 8:03116f75b66e 239 return 0;
simon 1:ac48b187213c 240 }
simon 1:ac48b187213c 241 }
simon 1:ac48b187213c 242
simon 1:ac48b187213c 243 int TextLCD::rows() {
simon 1:ac48b187213c 244 switch (_type) {
wim 8:03116f75b66e 245 case LCD8x1:
wim 8:03116f75b66e 246 return 1;
wim 8:03116f75b66e 247
wim 8:03116f75b66e 248 case LCD8x2:
simon 1:ac48b187213c 249 case LCD16x2:
simon 1:ac48b187213c 250 case LCD16x2B:
simon 1:ac48b187213c 251 case LCD20x2:
wim 8:03116f75b66e 252 case LCD24x2:
wim 9:0893d986e717 253 case LCD40x2:
wim 8:03116f75b66e 254 return 2;
wim 8:03116f75b66e 255
wim 8:03116f75b66e 256 case LCD16x4:
wim 8:03116f75b66e 257 case LCD20x4:
wim 8:03116f75b66e 258 return 4;
wim 8:03116f75b66e 259
simon 1:ac48b187213c 260 default:
wim 8:03116f75b66e 261 return 0;
simon 1:ac48b187213c 262 }
simon 1:ac48b187213c 263 }