Arief Jaya / TextLCD_test

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TextLCD.cpp@0:eebebe91fd28, 2020-06-19 (annotated)

Committer:
freezeburger
Date:
Fri Jun 19 15:11:14 2020 +0000
Revision:
0:eebebe91fd28
[mbed] converted /TextLCD/TextLCD

Who changed what in which revision?

UserRevisionLine numberNew contents of line
freezeburger 0:eebebe91fd28 1 /* mbed TextLCD Library
freezeburger 0:eebebe91fd28 2 * Copyright (c) 2007-2009 sford
freezeburger 0:eebebe91fd28 3 * Released under the MIT License: http://mbed.org/license/mit
freezeburger 0:eebebe91fd28 4 */
freezeburger 0:eebebe91fd28 5
freezeburger 0:eebebe91fd28 6 #include "TextLCD.h"
freezeburger 0:eebebe91fd28 7
freezeburger 0:eebebe91fd28 8 #include "mbed.h"
freezeburger 0:eebebe91fd28 9 #include "error.h"
freezeburger 0:eebebe91fd28 10
freezeburger 0:eebebe91fd28 11 using namespace mbed;
freezeburger 0:eebebe91fd28 12
freezeburger 0:eebebe91fd28 13 /*
freezeburger 0:eebebe91fd28 14 * useful info found at http://www.a-netz.de/lcd.en.php
freezeburger 0:eebebe91fd28 15 *
freezeburger 0:eebebe91fd28 16 *
freezeburger 0:eebebe91fd28 17 * Initialisation
freezeburger 0:eebebe91fd28 18 * ==============
freezeburger 0:eebebe91fd28 19 *
freezeburger 0:eebebe91fd28 20 * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state
freezeburger 0:eebebe91fd28 21 *
freezeburger 0:eebebe91fd28 22 * - wait approximately 15 ms so the display is ready to execute commands
freezeburger 0:eebebe91fd28 23 * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now).
freezeburger 0:eebebe91fd28 24 * - The display is in 8 bit mode, so if you have only connected 4 data pins you should only transmit the higher nibble of each command.
freezeburger 0:eebebe91fd28 25 * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now.
freezeburger 0:eebebe91fd28 26 * - Execute the "clear display" command
freezeburger 0:eebebe91fd28 27 *
freezeburger 0:eebebe91fd28 28 * Timing
freezeburger 0:eebebe91fd28 29 * ======
freezeburger 0:eebebe91fd28 30 *
freezeburger 0:eebebe91fd28 31 * Nearly all commands transmitted to the display need 40us for execution.
freezeburger 0:eebebe91fd28 32 * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position"
freezeburger 0:eebebe91fd28 33 * These commands need 1.64ms for execution. These timings are valid for all displays working with an
freezeburger 0:eebebe91fd28 34 * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you
freezeburger 0:eebebe91fd28 35 * can use the busy flag to test if the display is ready to accept the next command.
freezeburger 0:eebebe91fd28 36 *
freezeburger 0:eebebe91fd28 37 * _e is kept high apart from calling clock
freezeburger 0:eebebe91fd28 38 * _rw is kept 0 (write) apart from actions that uyse it differently
freezeburger 0:eebebe91fd28 39 * _rs is set by the data/command writes
freezeburger 0:eebebe91fd28 40 */
freezeburger 0:eebebe91fd28 41
freezeburger 0:eebebe91fd28 42 TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1,
freezeburger 0:eebebe91fd28 43 PinName d2, PinName d3, int columns, int rows) : _rw(rw), _rs(rs),
freezeburger 0:eebebe91fd28 44 _e(e), _d(d0, d1, d2, d3), _columns(columns), _rows(rows) {
freezeburger 0:eebebe91fd28 45
freezeburger 0:eebebe91fd28 46 // _rows = 2;
freezeburger 0:eebebe91fd28 47 // _columns = 16;
freezeburger 0:eebebe91fd28 48 // Mon, 27 Apr 2009 23:32:34 +0200
freezeburger 0:eebebe91fd28 49 // Kevin Konradt:
freezeburger 0:eebebe91fd28 50 // When using a LCD with 1 row x 16 characters
freezeburger 0:eebebe91fd28 51 // instead of 2x16, try changing _columns to 8.
freezeburger 0:eebebe91fd28 52 // (display seems to split the 16 characters into
freezeburger 0:eebebe91fd28 53 // 2 virtual rows with 8 characters each.)
freezeburger 0:eebebe91fd28 54
freezeburger 0:eebebe91fd28 55 _rw = 0;
freezeburger 0:eebebe91fd28 56 _e = 1;
freezeburger 0:eebebe91fd28 57 _rs = 0; // command mode
freezeburger 0:eebebe91fd28 58
freezeburger 0:eebebe91fd28 59 // Should theoretically wait 15ms, but most things will be powered up pre-reset
freezeburger 0:eebebe91fd28 60 // so i'll disable that for the minute. If implemented, could wait 15ms post reset
freezeburger 0:eebebe91fd28 61 // instead
freezeburger 0:eebebe91fd28 62 // wait(0.015);
freezeburger 0:eebebe91fd28 63
freezeburger 0:eebebe91fd28 64 // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
freezeburger 0:eebebe91fd28 65 for(int i=0; i<3; i++) {
freezeburger 0:eebebe91fd28 66 writeNibble(0x3);
freezeburger 0:eebebe91fd28 67 wait(0.00164); // this command takes 1.64ms, so wait for it
freezeburger 0:eebebe91fd28 68 }
freezeburger 0:eebebe91fd28 69 writeNibble(0x2); // 4-bit mode
freezeburger 0:eebebe91fd28 70
freezeburger 0:eebebe91fd28 71 writeCommand(0x28); // Function set 001 BW N F - -
freezeburger 0:eebebe91fd28 72 writeCommand(0x0C);
freezeburger 0:eebebe91fd28 73 writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
freezeburger 0:eebebe91fd28 74
freezeburger 0:eebebe91fd28 75 cls();
freezeburger 0:eebebe91fd28 76 }
freezeburger 0:eebebe91fd28 77
freezeburger 0:eebebe91fd28 78 int TextLCD::_putc(int value) {
freezeburger 0:eebebe91fd28 79 if(value == '\n') {
freezeburger 0:eebebe91fd28 80 newline();
freezeburger 0:eebebe91fd28 81 } else {
freezeburger 0:eebebe91fd28 82 writeData(value);
freezeburger 0:eebebe91fd28 83 }
freezeburger 0:eebebe91fd28 84 return value;
freezeburger 0:eebebe91fd28 85 }
freezeburger 0:eebebe91fd28 86
freezeburger 0:eebebe91fd28 87 int TextLCD::_getc() {
freezeburger 0:eebebe91fd28 88 return 0;
freezeburger 0:eebebe91fd28 89 }
freezeburger 0:eebebe91fd28 90
freezeburger 0:eebebe91fd28 91 void TextLCD::newline() {
freezeburger 0:eebebe91fd28 92 _column = 0;
freezeburger 0:eebebe91fd28 93 _row++;
freezeburger 0:eebebe91fd28 94 if(_row >= _rows) {
freezeburger 0:eebebe91fd28 95 _row = 0;
freezeburger 0:eebebe91fd28 96 }
freezeburger 0:eebebe91fd28 97 locate(_column, _row);
freezeburger 0:eebebe91fd28 98 }
freezeburger 0:eebebe91fd28 99
freezeburger 0:eebebe91fd28 100 void TextLCD::locate(int column, int row) {
freezeburger 0:eebebe91fd28 101 if(column < 0 || column >= _columns || row < 0 || row >= _rows) {
freezeburger 0:eebebe91fd28 102 error("locate(%d,%d) out of range on %dx%d display", column, row, _columns, _rows);
freezeburger 0:eebebe91fd28 103 return;
freezeburger 0:eebebe91fd28 104 }
freezeburger 0:eebebe91fd28 105
freezeburger 0:eebebe91fd28 106 _row = row;
freezeburger 0:eebebe91fd28 107 _column = column;
freezeburger 0:eebebe91fd28 108 int address = 0x80 + (_row * 40) + _column; // memory starts at 0x80, and is 40 chars long per row
freezeburger 0:eebebe91fd28 109 writeCommand(address);
freezeburger 0:eebebe91fd28 110 }
freezeburger 0:eebebe91fd28 111
freezeburger 0:eebebe91fd28 112 void TextLCD::cls() {
freezeburger 0:eebebe91fd28 113 writeCommand(0x01); // Clear Display
freezeburger 0:eebebe91fd28 114 wait(0.00164f); // This command takes 1.64 ms
freezeburger 0:eebebe91fd28 115 locate(0, 0);
freezeburger 0:eebebe91fd28 116 }
freezeburger 0:eebebe91fd28 117
freezeburger 0:eebebe91fd28 118 void TextLCD::reset() {
freezeburger 0:eebebe91fd28 119 cls();
freezeburger 0:eebebe91fd28 120 }
freezeburger 0:eebebe91fd28 121
freezeburger 0:eebebe91fd28 122 void TextLCD::clock() {
freezeburger 0:eebebe91fd28 123 wait(0.000040f);
freezeburger 0:eebebe91fd28 124 _e = 0;
freezeburger 0:eebebe91fd28 125 wait(0.000040f); // most instructions take 40us
freezeburger 0:eebebe91fd28 126 _e = 1;
freezeburger 0:eebebe91fd28 127 }
freezeburger 0:eebebe91fd28 128
freezeburger 0:eebebe91fd28 129 void TextLCD::writeNibble(int value) {
freezeburger 0:eebebe91fd28 130 _d = value;
freezeburger 0:eebebe91fd28 131 clock();
freezeburger 0:eebebe91fd28 132 }
freezeburger 0:eebebe91fd28 133
freezeburger 0:eebebe91fd28 134 void TextLCD::writeByte(int value) {
freezeburger 0:eebebe91fd28 135 writeNibble(value >> 4);
freezeburger 0:eebebe91fd28 136 writeNibble(value >> 0);
freezeburger 0:eebebe91fd28 137 }
freezeburger 0:eebebe91fd28 138
freezeburger 0:eebebe91fd28 139 void TextLCD::writeCommand(int command) {
freezeburger 0:eebebe91fd28 140 _rs = 0;
freezeburger 0:eebebe91fd28 141 writeByte(command);
freezeburger 0:eebebe91fd28 142 }
freezeburger 0:eebebe91fd28 143
freezeburger 0:eebebe91fd28 144 void TextLCD::writeData(int data) {
freezeburger 0:eebebe91fd28 145 _rs = 1;
freezeburger 0:eebebe91fd28 146 writeByte(data);
freezeburger 0:eebebe91fd28 147 _column++;
freezeburger 0:eebebe91fd28 148 if(_column >= _columns) {
freezeburger 0:eebebe91fd28 149 newline();
freezeburger 0:eebebe91fd28 150 }
freezeburger 0:eebebe91fd28 151 }