University of Plymouth - Stages 1, 2 and 3 / LCD-Winstar-WH1602B

TextLCD library for controlling various LCD panels based on the HD44780 4-bit interface. Forked for WH1602B

TextLCD.cpp@9:1c075b5dd4c9, 2019-10-21 (annotated)

Committer:
noutram
Date:
Mon Oct 21 11:49:25 2019 +0000
Revision:
9:1c075b5dd4c9
Parent:
7:44f34c09bd37 
Updated for Winstar WH1602B

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
simon 1:ac48b187213c 3 *
simon 1:ac48b187213c 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
simon 1:ac48b187213c 5 * of this software and associated documentation files (the "Software"), to deal
simon 1:ac48b187213c 6 * in the Software without restriction, including without limitation the rights
simon 1:ac48b187213c 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
simon 1:ac48b187213c 8 * copies of the Software, and to permit persons to whom the Software is
simon 1:ac48b187213c 9 * furnished to do so, subject to the following conditions:
simon 1:ac48b187213c 10 *
simon 1:ac48b187213c 11 * The above copyright notice and this permission notice shall be included in
simon 1:ac48b187213c 12 * all copies or substantial portions of the Software.
simon 1:ac48b187213c 13 *
simon 1:ac48b187213c 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
simon 1:ac48b187213c 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
simon 1:ac48b187213c 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
simon 1:ac48b187213c 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
simon 1:ac48b187213c 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
simon 1:ac48b187213c 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
simon 1:ac48b187213c 20 * THE SOFTWARE.
simon 1:ac48b187213c 21 */
simon 1:ac48b187213c 22
simon 1:ac48b187213c 23 #include "TextLCD.h"
simon 1:ac48b187213c 24 #include "mbed.h"
simon 1:ac48b187213c 25
simon 7:44f34c09bd37 26 TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
simon 7:44f34c09bd37 27 PinName d6, PinName d7, LCDType type) : _rs(rs),
simon 7:44f34c09bd37 28 _e(e), _d(d4, d5, d6, d7),
simon 1:ac48b187213c 29 _type(type) {
simon 1:ac48b187213c 30
simon 1:ac48b187213c 31 _e = 1;
simon 1:ac48b187213c 32 _rs = 0; // command mode
simon 1:ac48b187213c 33
noutram 9:1c075b5dd4c9 34 wait_us(40); // Wait for more than 40ms for power up
noutram 9:1c075b5dd4c9 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);
noutram 9:1c075b5dd4c9 40 wait_us(40);
noutram 9:1c075b5dd4c9 41 //wait(0.00164); // this command takes 1.64ms, so wait for it
simon 1:ac48b187213c 42 }
simon 1:ac48b187213c 43 writeByte(0x2); // 4-bit mode
noutram 9:1c075b5dd4c9 44 wait_us(40);
noutram 9:1c075b5dd4c9 45 //wait(0.000040f); // most instructions take 40us
simon 1:ac48b187213c 46
simon 1:ac48b187213c 47 writeCommand(0x28); // Function set 001 BW N F - -
simon 1:ac48b187213c 48 writeCommand(0x0C);
simon 1:ac48b187213c 49 writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
simon 1:ac48b187213c 50 cls();
simon 1:ac48b187213c 51 }
simon 1:ac48b187213c 52
simon 1:ac48b187213c 53 void TextLCD::character(int column, int row, int c) {
simon 1:ac48b187213c 54 int a = address(column, row);
simon 1:ac48b187213c 55 writeCommand(a);
simon 1:ac48b187213c 56 writeData(c);
simon 1:ac48b187213c 57 }
simon 1:ac48b187213c 58
simon 1:ac48b187213c 59 void TextLCD::cls() {
simon 1:ac48b187213c 60 writeCommand(0x01); // cls, and set cursor to 0
noutram 9:1c075b5dd4c9 61 wait_us(1640);
noutram 9:1c075b5dd4c9 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;
noutram 9:1c075b5dd4c9 98 wait_us(41);
noutram 9:1c075b5dd4c9 99 //wait(0.000040f); // most instructions take 40us
simon 1:ac48b187213c 100 _e = 0;
noutram 9:1c075b5dd4c9 101 wait_us(41);
noutram 9:1c075b5dd4c9 102 //wait(0.000040f);
simon 1:ac48b187213c 103 _e = 1;
simon 1:ac48b187213c 104 _d = value >> 0;
noutram 9:1c075b5dd4c9 105 wait_us(41);
noutram 9:1c075b5dd4c9 106 //wait(0.000040f);
simon 1:ac48b187213c 107 _e = 0;
noutram 9:1c075b5dd4c9 108 wait_us(41);
noutram 9:1c075b5dd4c9 109 //wait(0.000040f); // most instructions take 40us
simon 1:ac48b187213c 110 _e = 1;
simon 1:ac48b187213c 111 }
simon 1:ac48b187213c 112
simon 1:ac48b187213c 113 void TextLCD::writeCommand(int command) {
simon 1:ac48b187213c 114 _rs = 0;
simon 1:ac48b187213c 115 writeByte(command);
simon 1:ac48b187213c 116 }
simon 1:ac48b187213c 117
simon 1:ac48b187213c 118 void TextLCD::writeData(int data) {
simon 1:ac48b187213c 119 _rs = 1;
simon 1:ac48b187213c 120 writeByte(data);
simon 1:ac48b187213c 121 }
simon 1:ac48b187213c 122
simon 1:ac48b187213c 123 int TextLCD::address(int column, int row) {
simon 1:ac48b187213c 124 switch (_type) {
simon 1:ac48b187213c 125 case LCD20x4:
simon 1:ac48b187213c 126 switch (row) {
simon 1:ac48b187213c 127 case 0:
simon 1:ac48b187213c 128 return 0x80 + column;
simon 1:ac48b187213c 129 case 1:
simon 1:ac48b187213c 130 return 0xc0 + column;
simon 1:ac48b187213c 131 case 2:
simon 1:ac48b187213c 132 return 0x94 + column;
simon 1:ac48b187213c 133 case 3:
simon 1:ac48b187213c 134 return 0xd4 + column;
simon 1:ac48b187213c 135 }
simon 1:ac48b187213c 136 case LCD16x2B:
simon 4:bf5b706f8d32 137 return 0x80 + (row * 40) + column;
simon 1:ac48b187213c 138 case LCD16x2:
simon 1:ac48b187213c 139 case LCD20x2:
simon 1:ac48b187213c 140 default:
simon 4:bf5b706f8d32 141 return 0x80 + (row * 0x40) + column;
simon 1:ac48b187213c 142 }
simon 1:ac48b187213c 143 }
simon 1:ac48b187213c 144
simon 1:ac48b187213c 145 int TextLCD::columns() {
simon 1:ac48b187213c 146 switch (_type) {
simon 1:ac48b187213c 147 case LCD20x4:
simon 1:ac48b187213c 148 case LCD20x2:
simon 1:ac48b187213c 149 return 20;
simon 1:ac48b187213c 150 case LCD16x2:
simon 1:ac48b187213c 151 case LCD16x2B:
simon 1:ac48b187213c 152 default:
simon 1:ac48b187213c 153 return 16;
simon 1:ac48b187213c 154 }
simon 1:ac48b187213c 155 }
simon 1:ac48b187213c 156
simon 1:ac48b187213c 157 int TextLCD::rows() {
simon 1:ac48b187213c 158 switch (_type) {
simon 1:ac48b187213c 159 case LCD20x4:
simon 1:ac48b187213c 160 return 4;
simon 1:ac48b187213c 161 case LCD16x2:
simon 1:ac48b187213c 162 case LCD16x2B:
simon 1:ac48b187213c 163 case LCD20x2:
simon 1:ac48b187213c 164 default:
simon 1:ac48b187213c 165 return 2;
simon 1:ac48b187213c 166 }
simon 1:ac48b187213c 167 }