TextLCD library for controlling various LCD panels based on the HD44780 4-bit interface (does not contain blocking code)
Fork of TextLCD by
TextLCD.cpp@9:057d7d076a35, 2015-11-02 (annotated)
- Committer:
- abiswas25
- Date:
- Mon Nov 02 17:52:25 2015 +0000
- Revision:
- 9:057d7d076a35
- Parent:
- 7:44f34c09bd37
Removed wait statements (blocking code) which was causing problems while using with Ticker class (or any other class which prohibits use of blocking code)
Who changed what in which revision?
User | Revision | Line number | New 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 | |
abiswas25 | 9:057d7d076a35 | 34 | for(int z=0;z<240000;z++); // Wait 15ms to ensure powered up |
simon | 1:ac48b187213c | 35 | |
simon | 1:ac48b187213c | 36 | // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus) |
simon | 1:ac48b187213c | 37 | for (int i=0; i<3; i++) { |
simon | 1:ac48b187213c | 38 | writeByte(0x3); |
abiswas25 | 9:057d7d076a35 | 39 | for(int z=0;z<78720;z++); // this command takes 1.64ms, so wait for it |
simon | 1:ac48b187213c | 40 | } |
simon | 1:ac48b187213c | 41 | writeByte(0x2); // 4-bit mode |
abiswas25 | 9:057d7d076a35 | 42 | for(int z=0;z<1920;z++); // most instructions take 40us |
simon | 1:ac48b187213c | 43 | |
simon | 1:ac48b187213c | 44 | writeCommand(0x28); // Function set 001 BW N F - - |
simon | 1:ac48b187213c | 45 | writeCommand(0x0C); |
simon | 1:ac48b187213c | 46 | 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 | 47 | cls(); |
simon | 1:ac48b187213c | 48 | } |
simon | 1:ac48b187213c | 49 | |
simon | 1:ac48b187213c | 50 | void TextLCD::character(int column, int row, int c) { |
simon | 1:ac48b187213c | 51 | int a = address(column, row); |
simon | 1:ac48b187213c | 52 | writeCommand(a); |
simon | 1:ac48b187213c | 53 | writeData(c); |
simon | 1:ac48b187213c | 54 | } |
simon | 1:ac48b187213c | 55 | |
simon | 1:ac48b187213c | 56 | void TextLCD::cls() { |
simon | 1:ac48b187213c | 57 | writeCommand(0x01); // cls, and set cursor to 0 |
abiswas25 | 9:057d7d076a35 | 58 | for(int z=0;z<78720;z++); // This command takes 1.64 ms |
simon | 1:ac48b187213c | 59 | locate(0, 0); |
simon | 1:ac48b187213c | 60 | } |
simon | 1:ac48b187213c | 61 | |
simon | 1:ac48b187213c | 62 | void TextLCD::locate(int column, int row) { |
simon | 1:ac48b187213c | 63 | _column = column; |
simon | 1:ac48b187213c | 64 | _row = row; |
simon | 1:ac48b187213c | 65 | } |
simon | 1:ac48b187213c | 66 | |
simon | 1:ac48b187213c | 67 | int TextLCD::_putc(int value) { |
simon | 1:ac48b187213c | 68 | if (value == '\n') { |
simon | 1:ac48b187213c | 69 | _column = 0; |
simon | 1:ac48b187213c | 70 | _row++; |
simon | 1:ac48b187213c | 71 | if (_row >= rows()) { |
simon | 1:ac48b187213c | 72 | _row = 0; |
simon | 1:ac48b187213c | 73 | } |
simon | 1:ac48b187213c | 74 | } else { |
simon | 1:ac48b187213c | 75 | character(_column, _row, value); |
simon | 1:ac48b187213c | 76 | _column++; |
simon | 1:ac48b187213c | 77 | if (_column >= columns()) { |
simon | 1:ac48b187213c | 78 | _column = 0; |
simon | 1:ac48b187213c | 79 | _row++; |
simon | 1:ac48b187213c | 80 | if (_row >= rows()) { |
simon | 1:ac48b187213c | 81 | _row = 0; |
simon | 1:ac48b187213c | 82 | } |
simon | 1:ac48b187213c | 83 | } |
simon | 1:ac48b187213c | 84 | } |
simon | 1:ac48b187213c | 85 | return value; |
simon | 1:ac48b187213c | 86 | } |
simon | 1:ac48b187213c | 87 | |
simon | 1:ac48b187213c | 88 | int TextLCD::_getc() { |
simon | 1:ac48b187213c | 89 | return -1; |
simon | 1:ac48b187213c | 90 | } |
simon | 1:ac48b187213c | 91 | |
simon | 1:ac48b187213c | 92 | void TextLCD::writeByte(int value) { |
simon | 1:ac48b187213c | 93 | _d = value >> 4; |
abiswas25 | 9:057d7d076a35 | 94 | for(int z=0;z<1920;z++); // most instructions take 40us |
simon | 1:ac48b187213c | 95 | _e = 0; |
abiswas25 | 9:057d7d076a35 | 96 | for(int z=0;z<1920;z++); |
simon | 1:ac48b187213c | 97 | _e = 1; |
simon | 1:ac48b187213c | 98 | _d = value >> 0; |
abiswas25 | 9:057d7d076a35 | 99 | for(int z=0;z<1920;z++); |
simon | 1:ac48b187213c | 100 | _e = 0; |
abiswas25 | 9:057d7d076a35 | 101 | for(int z=0;z<1920;z++); // most instructions take 40us |
simon | 1:ac48b187213c | 102 | _e = 1; |
simon | 1:ac48b187213c | 103 | } |
simon | 1:ac48b187213c | 104 | |
simon | 1:ac48b187213c | 105 | void TextLCD::writeCommand(int command) { |
simon | 1:ac48b187213c | 106 | _rs = 0; |
simon | 1:ac48b187213c | 107 | writeByte(command); |
simon | 1:ac48b187213c | 108 | } |
simon | 1:ac48b187213c | 109 | |
simon | 1:ac48b187213c | 110 | void TextLCD::writeData(int data) { |
simon | 1:ac48b187213c | 111 | _rs = 1; |
simon | 1:ac48b187213c | 112 | writeByte(data); |
simon | 1:ac48b187213c | 113 | } |
simon | 1:ac48b187213c | 114 | |
simon | 1:ac48b187213c | 115 | int TextLCD::address(int column, int row) { |
simon | 1:ac48b187213c | 116 | switch (_type) { |
simon | 1:ac48b187213c | 117 | case LCD20x4: |
simon | 1:ac48b187213c | 118 | switch (row) { |
simon | 1:ac48b187213c | 119 | case 0: |
simon | 1:ac48b187213c | 120 | return 0x80 + column; |
simon | 1:ac48b187213c | 121 | case 1: |
simon | 1:ac48b187213c | 122 | return 0xc0 + column; |
simon | 1:ac48b187213c | 123 | case 2: |
simon | 1:ac48b187213c | 124 | return 0x94 + column; |
simon | 1:ac48b187213c | 125 | case 3: |
simon | 1:ac48b187213c | 126 | return 0xd4 + column; |
simon | 1:ac48b187213c | 127 | } |
simon | 1:ac48b187213c | 128 | case LCD16x2B: |
simon | 4:bf5b706f8d32 | 129 | return 0x80 + (row * 40) + column; |
simon | 1:ac48b187213c | 130 | case LCD16x2: |
simon | 1:ac48b187213c | 131 | case LCD20x2: |
simon | 1:ac48b187213c | 132 | default: |
simon | 4:bf5b706f8d32 | 133 | return 0x80 + (row * 0x40) + column; |
simon | 1:ac48b187213c | 134 | } |
simon | 1:ac48b187213c | 135 | } |
simon | 1:ac48b187213c | 136 | |
simon | 1:ac48b187213c | 137 | int TextLCD::columns() { |
simon | 1:ac48b187213c | 138 | switch (_type) { |
simon | 1:ac48b187213c | 139 | case LCD20x4: |
simon | 1:ac48b187213c | 140 | case LCD20x2: |
simon | 1:ac48b187213c | 141 | return 20; |
simon | 1:ac48b187213c | 142 | case LCD16x2: |
simon | 1:ac48b187213c | 143 | case LCD16x2B: |
simon | 1:ac48b187213c | 144 | default: |
simon | 1:ac48b187213c | 145 | return 16; |
simon | 1:ac48b187213c | 146 | } |
simon | 1:ac48b187213c | 147 | } |
simon | 1:ac48b187213c | 148 | |
simon | 1:ac48b187213c | 149 | int TextLCD::rows() { |
simon | 1:ac48b187213c | 150 | switch (_type) { |
simon | 1:ac48b187213c | 151 | case LCD20x4: |
simon | 1:ac48b187213c | 152 | return 4; |
simon | 1:ac48b187213c | 153 | case LCD16x2: |
simon | 1:ac48b187213c | 154 | case LCD16x2B: |
simon | 1:ac48b187213c | 155 | case LCD20x2: |
simon | 1:ac48b187213c | 156 | default: |
simon | 1:ac48b187213c | 157 | return 2; |
simon | 1:ac48b187213c | 158 | } |
simon | 1:ac48b187213c | 159 | } |