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TextLCD.cpp@0:dabc223d3e03, 2012-06-13 (annotated)

Committer:: satriabtp
Date:: Wed Jun 13 08:51:44 2012 +0000
Revision:: 0:dabc223d3e03

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User	Revision	Line number	New contents of line
satriabtp	0:dabc223d3e03	1	/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
satriabtp	0:dabc223d3e03	2	* Copyright (c) 2007-2010, sford, http://mbed.org
satriabtp	0:dabc223d3e03	3	*
satriabtp	0:dabc223d3e03	4	* Permission is hereby granted, free of charge, to any person obtaining a copy
satriabtp	0:dabc223d3e03	5	* of this software and associated documentation files (the "Software"), to deal
satriabtp	0:dabc223d3e03	6	* in the Software without restriction, including without limitation the rights
satriabtp	0:dabc223d3e03	7	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
satriabtp	0:dabc223d3e03	8	* copies of the Software, and to permit persons to whom the Software is
satriabtp	0:dabc223d3e03	9	* furnished to do so, subject to the following conditions:
satriabtp	0:dabc223d3e03	10	*
satriabtp	0:dabc223d3e03	11	* The above copyright notice and this permission notice shall be included in
satriabtp	0:dabc223d3e03	12	* all copies or substantial portions of the Software.
satriabtp	0:dabc223d3e03	13	*
satriabtp	0:dabc223d3e03	14	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
satriabtp	0:dabc223d3e03	15	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
satriabtp	0:dabc223d3e03	16	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
satriabtp	0:dabc223d3e03	17	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
satriabtp	0:dabc223d3e03	18	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
satriabtp	0:dabc223d3e03	19	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
satriabtp	0:dabc223d3e03	20	* THE SOFTWARE.
satriabtp	0:dabc223d3e03	21	*/
satriabtp	0:dabc223d3e03	22
satriabtp	0:dabc223d3e03	23	#include "TextLCD.h"
satriabtp	0:dabc223d3e03	24	#include "mbed.h"
satriabtp	0:dabc223d3e03	25
satriabtp	0:dabc223d3e03	26	TextLCD::TextLCD(PinName rs, PinName e, PinName d0, PinName d1,
satriabtp	0:dabc223d3e03	27	PinName d2, PinName d3, LCDType type) : _rs(rs),
satriabtp	0:dabc223d3e03	28	_e(e), _d(d0, d1, d2, d3),
satriabtp	0:dabc223d3e03	29	_type(type) {
satriabtp	0:dabc223d3e03	30
satriabtp	0:dabc223d3e03	31	_e = 1;
satriabtp	0:dabc223d3e03	32	_rs = 0; // command mode
satriabtp	0:dabc223d3e03	33
satriabtp	0:dabc223d3e03	34	wait(0.015); // Wait 15ms to ensure powered up
satriabtp	0:dabc223d3e03	35
satriabtp	0:dabc223d3e03	36	// send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
satriabtp	0:dabc223d3e03	37	for (int i=0; i<3; i++) {
satriabtp	0:dabc223d3e03	38	writeByte(0x3);
satriabtp	0:dabc223d3e03	39	wait(0.00164); // this command takes 1.64ms, so wait for it
satriabtp	0:dabc223d3e03	40	}
satriabtp	0:dabc223d3e03	41	writeByte(0x2); // 4-bit mode
satriabtp	0:dabc223d3e03	42	wait(0.000040f); // most instructions take 40us
satriabtp	0:dabc223d3e03	43
satriabtp	0:dabc223d3e03	44	writeCommand(0x28); // Function set 001 BW N F - -
satriabtp	0:dabc223d3e03	45	writeCommand(0x0C);
satriabtp	0:dabc223d3e03	46	writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
satriabtp	0:dabc223d3e03	47	cls();
satriabtp	0:dabc223d3e03	48	}
satriabtp	0:dabc223d3e03	49
satriabtp	0:dabc223d3e03	50	void TextLCD::character(int column, int row, int c) {
satriabtp	0:dabc223d3e03	51	int a = address(column, row);
satriabtp	0:dabc223d3e03	52	writeCommand(a);
satriabtp	0:dabc223d3e03	53	writeData(c);
satriabtp	0:dabc223d3e03	54	}
satriabtp	0:dabc223d3e03	55
satriabtp	0:dabc223d3e03	56	void TextLCD::cls() {
satriabtp	0:dabc223d3e03	57	writeCommand(0x01); // cls, and set cursor to 0
satriabtp	0:dabc223d3e03	58	wait(0.00164f); // This command takes 1.64 ms
satriabtp	0:dabc223d3e03	59	locate(0, 0);
satriabtp	0:dabc223d3e03	60	}
satriabtp	0:dabc223d3e03	61
satriabtp	0:dabc223d3e03	62	void TextLCD::locate(int column, int row) {
satriabtp	0:dabc223d3e03	63	_column = column;
satriabtp	0:dabc223d3e03	64	_row = row;
satriabtp	0:dabc223d3e03	65	}
satriabtp	0:dabc223d3e03	66
satriabtp	0:dabc223d3e03	67	int TextLCD::_putc(int value) {
satriabtp	0:dabc223d3e03	68	if (value == '\n') {
satriabtp	0:dabc223d3e03	69	_column = 0;
satriabtp	0:dabc223d3e03	70	_row++;
satriabtp	0:dabc223d3e03	71	if (_row >= rows()) {
satriabtp	0:dabc223d3e03	72	_row = 0;
satriabtp	0:dabc223d3e03	73	}
satriabtp	0:dabc223d3e03	74	} else {
satriabtp	0:dabc223d3e03	75	character(_column, _row, value);
satriabtp	0:dabc223d3e03	76	_column++;
satriabtp	0:dabc223d3e03	77	if (_column >= columns()) {
satriabtp	0:dabc223d3e03	78	_column = 0;
satriabtp	0:dabc223d3e03	79	_row++;
satriabtp	0:dabc223d3e03	80	if (_row >= rows()) {
satriabtp	0:dabc223d3e03	81	_row = 0;
satriabtp	0:dabc223d3e03	82	}
satriabtp	0:dabc223d3e03	83	}
satriabtp	0:dabc223d3e03	84	}
satriabtp	0:dabc223d3e03	85	return value;
satriabtp	0:dabc223d3e03	86	}
satriabtp	0:dabc223d3e03	87
satriabtp	0:dabc223d3e03	88	int TextLCD::_getc() {
satriabtp	0:dabc223d3e03	89	return -1;
satriabtp	0:dabc223d3e03	90	}
satriabtp	0:dabc223d3e03	91
satriabtp	0:dabc223d3e03	92	void TextLCD::writeByte(int value) {
satriabtp	0:dabc223d3e03	93	_d = value >> 4;
satriabtp	0:dabc223d3e03	94	wait(0.000040f); // most instructions take 40us
satriabtp	0:dabc223d3e03	95	_e = 0;
satriabtp	0:dabc223d3e03	96	wait(0.000040f);
satriabtp	0:dabc223d3e03	97	_e = 1;
satriabtp	0:dabc223d3e03	98	_d = value >> 0;
satriabtp	0:dabc223d3e03	99	wait(0.000040f);
satriabtp	0:dabc223d3e03	100	_e = 0;
satriabtp	0:dabc223d3e03	101	wait(0.000040f); // most instructions take 40us
satriabtp	0:dabc223d3e03	102	_e = 1;
satriabtp	0:dabc223d3e03	103	}
satriabtp	0:dabc223d3e03	104
satriabtp	0:dabc223d3e03	105	void TextLCD::writeCommand(int command) {
satriabtp	0:dabc223d3e03	106	_rs = 0;
satriabtp	0:dabc223d3e03	107	writeByte(command);
satriabtp	0:dabc223d3e03	108	}
satriabtp	0:dabc223d3e03	109
satriabtp	0:dabc223d3e03	110	void TextLCD::writeData(int data) {
satriabtp	0:dabc223d3e03	111	_rs = 1;
satriabtp	0:dabc223d3e03	112	writeByte(data);
satriabtp	0:dabc223d3e03	113	}
satriabtp	0:dabc223d3e03	114
satriabtp	0:dabc223d3e03	115	int TextLCD::address(int column, int row) {
satriabtp	0:dabc223d3e03	116	switch (_type) {
satriabtp	0:dabc223d3e03	117	case LCD20x4:
satriabtp	0:dabc223d3e03	118	switch (row) {
satriabtp	0:dabc223d3e03	119	case 0:
satriabtp	0:dabc223d3e03	120	return 0x80 + column;
satriabtp	0:dabc223d3e03	121	case 1:
satriabtp	0:dabc223d3e03	122	return 0xc0 + column;
satriabtp	0:dabc223d3e03	123	case 2:
satriabtp	0:dabc223d3e03	124	return 0x94 + column;
satriabtp	0:dabc223d3e03	125	case 3:
satriabtp	0:dabc223d3e03	126	return 0xd4 + column;
satriabtp	0:dabc223d3e03	127	}
satriabtp	0:dabc223d3e03	128	case LCD16x2B:
satriabtp	0:dabc223d3e03	129	return 0x80 + (row * 40) + column;
satriabtp	0:dabc223d3e03	130	case LCD16x2:
satriabtp	0:dabc223d3e03	131	case LCD20x2:
satriabtp	0:dabc223d3e03	132	default:
satriabtp	0:dabc223d3e03	133	return 0x80 + (row * 0x40) + column;
satriabtp	0:dabc223d3e03	134	}
satriabtp	0:dabc223d3e03	135	}
satriabtp	0:dabc223d3e03	136
satriabtp	0:dabc223d3e03	137	int TextLCD::columns() {
satriabtp	0:dabc223d3e03	138	switch (_type) {
satriabtp	0:dabc223d3e03	139	case LCD20x4:
satriabtp	0:dabc223d3e03	140	case LCD20x2:
satriabtp	0:dabc223d3e03	141	return 20;
satriabtp	0:dabc223d3e03	142	case LCD16x2:
satriabtp	0:dabc223d3e03	143	case LCD16x2B:
satriabtp	0:dabc223d3e03	144	default:
satriabtp	0:dabc223d3e03	145	return 16;
satriabtp	0:dabc223d3e03	146	}
satriabtp	0:dabc223d3e03	147	}
satriabtp	0:dabc223d3e03	148
satriabtp	0:dabc223d3e03	149	int TextLCD::rows() {
satriabtp	0:dabc223d3e03	150	switch (_type) {
satriabtp	0:dabc223d3e03	151	case LCD20x4:
satriabtp	0:dabc223d3e03	152	return 4;
satriabtp	0:dabc223d3e03	153	case LCD16x2:
satriabtp	0:dabc223d3e03	154	case LCD16x2B:
satriabtp	0:dabc223d3e03	155	case LCD20x2:
satriabtp	0:dabc223d3e03	156	default:
satriabtp	0:dabc223d3e03	157	return 2;
satriabtp	0:dabc223d3e03	158	}
satriabtp	0:dabc223d3e03	159	}

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Type:	Library
Created:	13 Jun 2012
Imports:	290
Forks:	0
Commits:	1
Dependents:	1
Dependencies:	0
Followers:	6

TextLCD.cpp@0:dabc223d3e03, 2012-06-13 (annotated)

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