Dependencies:   ChaNFSSD mbed BMP085 SHT2x

Committer:
tosihisa
Date:
Mon Dec 26 15:58:32 2011 +0000
Revision:
0:6089ae824f06
1st Release

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tosihisa 0:6089ae824f06 1 /* mbed TextLCD Library
tosihisa 0:6089ae824f06 2 * Copyright (c) 2007-2009 sford
tosihisa 0:6089ae824f06 3 * Released under the MIT License: http://mbed.org/license/mit
tosihisa 0:6089ae824f06 4 *
tosihisa 0:6089ae824f06 5 * TODO: Needs serious rework/neatening up!
tosihisa 0:6089ae824f06 6 */
tosihisa 0:6089ae824f06 7
tosihisa 0:6089ae824f06 8 /*
tosihisa 0:6089ae824f06 9 * 2010/05/14 modified for 20X4 LCD by ym1784
tosihisa 0:6089ae824f06 10 */
tosihisa 0:6089ae824f06 11
tosihisa 0:6089ae824f06 12 #include "TextLCD_20X4.h"
tosihisa 0:6089ae824f06 13
tosihisa 0:6089ae824f06 14 #include "mbed.h"
tosihisa 0:6089ae824f06 15 #include "error.h"
tosihisa 0:6089ae824f06 16
tosihisa 0:6089ae824f06 17 using namespace mbed;
tosihisa 0:6089ae824f06 18
tosihisa 0:6089ae824f06 19 /*
tosihisa 0:6089ae824f06 20 * useful info found at http://www.a-netz.de/lcd.en.php
tosihisa 0:6089ae824f06 21 *
tosihisa 0:6089ae824f06 22 *
tosihisa 0:6089ae824f06 23 * Initialization
tosihisa 0:6089ae824f06 24 * ==============
tosihisa 0:6089ae824f06 25 *
tosihisa 0:6089ae824f06 26 * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state
tosihisa 0:6089ae824f06 27 *
tosihisa 0:6089ae824f06 28 * - wait approximately 15 ms so the display is ready to execute commands
tosihisa 0:6089ae824f06 29 * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now).
tosihisa 0:6089ae824f06 30 * - 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.
tosihisa 0:6089ae824f06 31 * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now.
tosihisa 0:6089ae824f06 32 * - Execute the "clear display" command
tosihisa 0:6089ae824f06 33 *
tosihisa 0:6089ae824f06 34 * Timing
tosihisa 0:6089ae824f06 35 * ======
tosihisa 0:6089ae824f06 36 *
tosihisa 0:6089ae824f06 37 * Nearly all commands transmitted to the display need 40us for execution.
tosihisa 0:6089ae824f06 38 * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position"
tosihisa 0:6089ae824f06 39 * These commands need 1.64ms for execution. These timings are valid for all displays working with an
tosihisa 0:6089ae824f06 40 * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you
tosihisa 0:6089ae824f06 41 * can use the busy flag to test if the display is ready to accept the next command.
tosihisa 0:6089ae824f06 42 *
tosihisa 0:6089ae824f06 43 * _e is kept high apart from calling clock
tosihisa 0:6089ae824f06 44 * _rw is kept 0 (write) apart from actions that uyse it differently
tosihisa 0:6089ae824f06 45 * -> on this program, the _rw is not used ... ym1784
tosihisa 0:6089ae824f06 46 * _rs is set by the data/command writes
tosihisa 0:6089ae824f06 47 */
tosihisa 0:6089ae824f06 48
tosihisa 0:6089ae824f06 49 TextLCD_20X4::TextLCD_20X4(PinName rs, PinName e, PinName d0, PinName d1,
tosihisa 0:6089ae824f06 50 PinName d2, PinName d3, int columns, int rows) : _rs(rs), _e(e), _d(d0, d1, d2, d3),
tosihisa 0:6089ae824f06 51 _columns(columns), _rows(rows) {
tosihisa 0:6089ae824f06 52
tosihisa 0:6089ae824f06 53 _rows = 4;
tosihisa 0:6089ae824f06 54 _columns = 20;
tosihisa 0:6089ae824f06 55 // Mon, 27 Apr 2009 23:32:34 +0200
tosihisa 0:6089ae824f06 56 // Kevin Konradt:
tosihisa 0:6089ae824f06 57 // When using a LCD with 1 row x 16 characters
tosihisa 0:6089ae824f06 58 // instead of 2x16, try changing _columns to 8.
tosihisa 0:6089ae824f06 59 // (display seems to split the 16 characters into
tosihisa 0:6089ae824f06 60 // 2 virtual rows with 8 characters each.)
tosihisa 0:6089ae824f06 61 //
tosihisa 0:6089ae824f06 62 // 2010/05/14 ym1784
tosihisa 0:6089ae824f06 63 // This program is only for 4 rows x 20 characters specific
tosihisa 0:6089ae824f06 64
tosihisa 0:6089ae824f06 65 // _rw = 0; // on this program, the _rw is not used ... ym1784
tosihisa 0:6089ae824f06 66 _e = 1;
tosihisa 0:6089ae824f06 67 _rs = 0; // command mode
tosihisa 0:6089ae824f06 68
tosihisa 0:6089ae824f06 69 // Should theoretically wait 15ms, but most things will be powered up pre-reset
tosihisa 0:6089ae824f06 70 // so i'll disable that for the minute. If implemented, could wait 15ms post reset
tosihisa 0:6089ae824f06 71 // instead
tosihisa 0:6089ae824f06 72 wait(0.015); // for safety ... ym1784
tosihisa 0:6089ae824f06 73
tosihisa 0:6089ae824f06 74 // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
tosihisa 0:6089ae824f06 75 for(int i=0; i<3; i++) {
tosihisa 0:6089ae824f06 76 writeNibble(0x3);
tosihisa 0:6089ae824f06 77 wait(0.00164); // this command takes 1.64ms, so wait for it
tosihisa 0:6089ae824f06 78 }
tosihisa 0:6089ae824f06 79 writeNibble(0x2); // 4-bit mode
tosihisa 0:6089ae824f06 80
tosihisa 0:6089ae824f06 81 writeCommand(0x28); // Function set 001 BW N F - -
tosihisa 0:6089ae824f06 82 writeCommand(0x0C);
tosihisa 0:6089ae824f06 83 writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
tosihisa 0:6089ae824f06 84
tosihisa 0:6089ae824f06 85 cls();
tosihisa 0:6089ae824f06 86 }
tosihisa 0:6089ae824f06 87
tosihisa 0:6089ae824f06 88 int TextLCD_20X4::_putc(int value) {
tosihisa 0:6089ae824f06 89 if(value == '\n') {
tosihisa 0:6089ae824f06 90 newline();
tosihisa 0:6089ae824f06 91 } else {
tosihisa 0:6089ae824f06 92 writeData(value);
tosihisa 0:6089ae824f06 93 }
tosihisa 0:6089ae824f06 94 return value;
tosihisa 0:6089ae824f06 95 }
tosihisa 0:6089ae824f06 96
tosihisa 0:6089ae824f06 97 int TextLCD_20X4::_getc() {
tosihisa 0:6089ae824f06 98 return 0;
tosihisa 0:6089ae824f06 99 }
tosihisa 0:6089ae824f06 100
tosihisa 0:6089ae824f06 101 void TextLCD_20X4::newline() {
tosihisa 0:6089ae824f06 102 _column = 0;
tosihisa 0:6089ae824f06 103 _row++;
tosihisa 0:6089ae824f06 104 if(_row >= _rows) {
tosihisa 0:6089ae824f06 105 _row = 0;
tosihisa 0:6089ae824f06 106 }
tosihisa 0:6089ae824f06 107 locate(_column, _row);
tosihisa 0:6089ae824f06 108 }
tosihisa 0:6089ae824f06 109
tosihisa 0:6089ae824f06 110 void TextLCD_20X4::locate(int column, int row) {
tosihisa 0:6089ae824f06 111 if(column < 0 || column >= _columns || row < 0 || row >= _rows) {
tosihisa 0:6089ae824f06 112 error("locate(%d,%d) out of range on %dx%d display", column, row, _columns, _rows);
tosihisa 0:6089ae824f06 113 return;
tosihisa 0:6089ae824f06 114 }
tosihisa 0:6089ae824f06 115 _row = row;
tosihisa 0:6089ae824f06 116 _column = column;
tosihisa 0:6089ae824f06 117 // modified for 20X4 LCD
tosihisa 0:6089ae824f06 118 switch (_row) {
tosihisa 0:6089ae824f06 119 case (0) : address = 0x80 + _column;
tosihisa 0:6089ae824f06 120 break;
tosihisa 0:6089ae824f06 121 case (1) : address = 0xc0 + _column;
tosihisa 0:6089ae824f06 122 break;
tosihisa 0:6089ae824f06 123 case (2) : address = 0x94 + _column;
tosihisa 0:6089ae824f06 124 break;
tosihisa 0:6089ae824f06 125 case (3) : address = 0xd4 + _column;
tosihisa 0:6089ae824f06 126 break;
tosihisa 0:6089ae824f06 127 } // switch
tosihisa 0:6089ae824f06 128 writeCommand(address);
tosihisa 0:6089ae824f06 129 }
tosihisa 0:6089ae824f06 130
tosihisa 0:6089ae824f06 131 void TextLCD_20X4::cls() {
tosihisa 0:6089ae824f06 132 writeCommand(0x01); // Clear Display
tosihisa 0:6089ae824f06 133 wait(0.00164f); // This command takes 1.64 ms
tosihisa 0:6089ae824f06 134 // locate(0, 0); // We don't have to do this here
tosihisa 0:6089ae824f06 135 }
tosihisa 0:6089ae824f06 136
tosihisa 0:6089ae824f06 137 void TextLCD_20X4::reset() {
tosihisa 0:6089ae824f06 138 cls();
tosihisa 0:6089ae824f06 139 }
tosihisa 0:6089ae824f06 140
tosihisa 0:6089ae824f06 141 void TextLCD_20X4::clock() {
tosihisa 0:6089ae824f06 142 wait(0.000040f);
tosihisa 0:6089ae824f06 143 _e = 0;
tosihisa 0:6089ae824f06 144 wait(0.000040f); // most instructions take 40us
tosihisa 0:6089ae824f06 145 _e = 1;
tosihisa 0:6089ae824f06 146 }
tosihisa 0:6089ae824f06 147
tosihisa 0:6089ae824f06 148 void TextLCD_20X4::writeNibble(int value) {
tosihisa 0:6089ae824f06 149 _d = value;
tosihisa 0:6089ae824f06 150 clock();
tosihisa 0:6089ae824f06 151 }
tosihisa 0:6089ae824f06 152
tosihisa 0:6089ae824f06 153 void TextLCD_20X4::writeByte(int value) {
tosihisa 0:6089ae824f06 154 writeNibble(value >> 4);
tosihisa 0:6089ae824f06 155 writeNibble(value >> 0);
tosihisa 0:6089ae824f06 156 }
tosihisa 0:6089ae824f06 157
tosihisa 0:6089ae824f06 158 void TextLCD_20X4::writeCommand(int command) {
tosihisa 0:6089ae824f06 159 _rs = 0;
tosihisa 0:6089ae824f06 160 writeByte(command);
tosihisa 0:6089ae824f06 161 }
tosihisa 0:6089ae824f06 162
tosihisa 0:6089ae824f06 163 void TextLCD_20X4::writeData(int data) {
tosihisa 0:6089ae824f06 164 _rs = 1;
tosihisa 0:6089ae824f06 165 writeByte(data);
tosihisa 0:6089ae824f06 166 _column++;
tosihisa 0:6089ae824f06 167 if(_column >= _columns) {
tosihisa 0:6089ae824f06 168 newline();
tosihisa 0:6089ae824f06 169 }
tosihisa 0:6089ae824f06 170 }