TextLCD - | Mbed

Users » intrinseca » Code » TextLCD

Dependents: FBRDash1 FBRDash-tom FBRDash

TextLCD.cpp@0:006bcd28cc39, 2012-03-21 (annotated)

Committer:: intrinseca
Date:: Wed Mar 21 23:55:03 2012 +0000
Revision:: 0:006bcd28cc39

Who changed what in which revision?

User	Revision	Line number	New contents of line
intrinseca	0:006bcd28cc39	1	/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
intrinseca	0:006bcd28cc39	2	* Copyright (c) 2007-2010, sford, http://mbed.org
intrinseca	0:006bcd28cc39	3	*
intrinseca	0:006bcd28cc39	4	* Permission is hereby granted, free of charge, to any person obtaining a copy
intrinseca	0:006bcd28cc39	5	* of this software and associated documentation files (the "Software"), to deal
intrinseca	0:006bcd28cc39	6	* in the Software without restriction, including without limitation the rights
intrinseca	0:006bcd28cc39	7	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
intrinseca	0:006bcd28cc39	8	* copies of the Software, and to permit persons to whom the Software is
intrinseca	0:006bcd28cc39	9	* furnished to do so, subject to the following conditions:
intrinseca	0:006bcd28cc39	10	*
intrinseca	0:006bcd28cc39	11	* The above copyright notice and this permission notice shall be included in
intrinseca	0:006bcd28cc39	12	* all copies or substantial portions of the Software.
intrinseca	0:006bcd28cc39	13	*
intrinseca	0:006bcd28cc39	14	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
intrinseca	0:006bcd28cc39	15	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
intrinseca	0:006bcd28cc39	16	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
intrinseca	0:006bcd28cc39	17	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
intrinseca	0:006bcd28cc39	18	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
intrinseca	0:006bcd28cc39	19	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
intrinseca	0:006bcd28cc39	20	* THE SOFTWARE.
intrinseca	0:006bcd28cc39	21	*/
intrinseca	0:006bcd28cc39	22
intrinseca	0:006bcd28cc39	23	#include "TextLCD.h"
intrinseca	0:006bcd28cc39	24	#include "mbed.h"
intrinseca	0:006bcd28cc39	25
intrinseca	0:006bcd28cc39	26	TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1,
intrinseca	0:006bcd28cc39	27	PinName d2, PinName d3, LCDType type) : _rs(rs), _rw(rw),
intrinseca	0:006bcd28cc39	28	_e(e), _d(d0, d1, d2, d3), _type(type) {
intrinseca	0:006bcd28cc39	29	_rs = 0; // command mode
intrinseca	0:006bcd28cc39	30	_rw = 0;
intrinseca	0:006bcd28cc39	31	_e = 0;
intrinseca	0:006bcd28cc39	32	_d.output(); // data out
intrinseca	0:006bcd28cc39	33
intrinseca	0:006bcd28cc39	34	wait(0.05); // Wait 50ms to ensure powered up
intrinseca	0:006bcd28cc39	35
intrinseca	0:006bcd28cc39	36	// send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
intrinseca	0:006bcd28cc39	37	for (int i=0; i<3; i++) {
intrinseca	0:006bcd28cc39	38	_e = 1;
intrinseca	0:006bcd28cc39	39	__nop();
intrinseca	0:006bcd28cc39	40	_d = 0x3;
intrinseca	0:006bcd28cc39	41	__nop();
intrinseca	0:006bcd28cc39	42	_e = 0;
intrinseca	0:006bcd28cc39	43	wait(0.004f); // 4ms
intrinseca	0:006bcd28cc39	44	}
intrinseca	0:006bcd28cc39	45	_e = 1;
intrinseca	0:006bcd28cc39	46	__nop();
intrinseca	0:006bcd28cc39	47	_d = 0x2; // 4 Bit mode
intrinseca	0:006bcd28cc39	48	__nop();
intrinseca	0:006bcd28cc39	49	_e = 0;
intrinseca	0:006bcd28cc39	50
intrinseca	0:006bcd28cc39	51	writeCommand(0x28); // Function set 4 Bit, 2Line, 5*7
intrinseca	0:006bcd28cc39	52	writeCommand(0x08); // Display off
intrinseca	0:006bcd28cc39	53	writeCommand(0x01); // clear Display
intrinseca	0:006bcd28cc39	54	writeCommand(0x04); // cursor right, Display is not shifted
intrinseca	0:006bcd28cc39	55	writeCommand(0x0C); // Display on , Cursor off
intrinseca	0:006bcd28cc39	56	}
intrinseca	0:006bcd28cc39	57
intrinseca	0:006bcd28cc39	58	void TextLCD::character(int column, int row, int c) {
intrinseca	0:006bcd28cc39	59	int a = address(column, row);
intrinseca	0:006bcd28cc39	60	writeCommand(a);
intrinseca	0:006bcd28cc39	61	writeData(c);
intrinseca	0:006bcd28cc39	62	}
intrinseca	0:006bcd28cc39	63
intrinseca	0:006bcd28cc39	64	void TextLCD::cls() {
intrinseca	0:006bcd28cc39	65	writeCommand(0x01); // cls, and set cursor to 0
intrinseca	0:006bcd28cc39	66	locate(0, 0);
intrinseca	0:006bcd28cc39	67	}
intrinseca	0:006bcd28cc39	68
intrinseca	0:006bcd28cc39	69	void TextLCD::locate(int column, int row) {
intrinseca	0:006bcd28cc39	70	_column = column;
intrinseca	0:006bcd28cc39	71	_row = row;
intrinseca	0:006bcd28cc39	72	}
intrinseca	0:006bcd28cc39	73
intrinseca	0:006bcd28cc39	74
intrinseca	0:006bcd28cc39	75
intrinseca	0:006bcd28cc39	76	int TextLCD::_putc(int value) {
intrinseca	0:006bcd28cc39	77	if (value == '\n') {
intrinseca	0:006bcd28cc39	78	_column = 0;
intrinseca	0:006bcd28cc39	79	_row++;
intrinseca	0:006bcd28cc39	80	if (_row >= rows()) {
intrinseca	0:006bcd28cc39	81	_row = 0;
intrinseca	0:006bcd28cc39	82	}
intrinseca	0:006bcd28cc39	83	} else {
intrinseca	0:006bcd28cc39	84	character(_column, _row, value);
intrinseca	0:006bcd28cc39	85	_column++;
intrinseca	0:006bcd28cc39	86	if (_column >= columns()) {
intrinseca	0:006bcd28cc39	87	_column = 0;
intrinseca	0:006bcd28cc39	88	_row++;
intrinseca	0:006bcd28cc39	89	if (_row >= rows()) {
intrinseca	0:006bcd28cc39	90	_row = 0;
intrinseca	0:006bcd28cc39	91	}
intrinseca	0:006bcd28cc39	92	}
intrinseca	0:006bcd28cc39	93	}
intrinseca	0:006bcd28cc39	94	return value;
intrinseca	0:006bcd28cc39	95	}
intrinseca	0:006bcd28cc39	96
intrinseca	0:006bcd28cc39	97	int TextLCD::_getc() {
intrinseca	0:006bcd28cc39	98	int a = address(_column, _row);
intrinseca	0:006bcd28cc39	99	writeCommand(a);
intrinseca	0:006bcd28cc39	100	return (readData());
intrinseca	0:006bcd28cc39	101	}
intrinseca	0:006bcd28cc39	102
intrinseca	0:006bcd28cc39	103	void TextLCD::writeByte(int value) {
intrinseca	0:006bcd28cc39	104	_e = 1;
intrinseca	0:006bcd28cc39	105	__nop();
intrinseca	0:006bcd28cc39	106	_d = value >> 4;
intrinseca	0:006bcd28cc39	107	__nop();
intrinseca	0:006bcd28cc39	108	_e = 0;
intrinseca	0:006bcd28cc39	109	__nop();
intrinseca	0:006bcd28cc39	110	_e = 1;
intrinseca	0:006bcd28cc39	111	__nop();
intrinseca	0:006bcd28cc39	112	_d = value >> 0;
intrinseca	0:006bcd28cc39	113	__nop();
intrinseca	0:006bcd28cc39	114	_e = 0;
intrinseca	0:006bcd28cc39	115	}
intrinseca	0:006bcd28cc39	116
intrinseca	0:006bcd28cc39	117	void TextLCD::writeCommand(int command) {
intrinseca	0:006bcd28cc39	118	waitBusy(); // check if display is ready
intrinseca	0:006bcd28cc39	119	_rs = 0;
intrinseca	0:006bcd28cc39	120	writeByte(command);
intrinseca	0:006bcd28cc39	121	}
intrinseca	0:006bcd28cc39	122
intrinseca	0:006bcd28cc39	123	int TextLCD::readData(){
intrinseca	0:006bcd28cc39	124	int input;
intrinseca	0:006bcd28cc39	125	waitBusy();
intrinseca	0:006bcd28cc39	126	_rw = 1;
intrinseca	0:006bcd28cc39	127	_rs = 1;
intrinseca	0:006bcd28cc39	128	__nop();
intrinseca	0:006bcd28cc39	129	_d.input(); // switch Data port to input
intrinseca	0:006bcd28cc39	130	_e = 1;
intrinseca	0:006bcd28cc39	131	__nop();
intrinseca	0:006bcd28cc39	132	input = _d.read() << 4; // high nibble
intrinseca	0:006bcd28cc39	133	_e = 0;
intrinseca	0:006bcd28cc39	134	__nop();
intrinseca	0:006bcd28cc39	135	_e = 1;
intrinseca	0:006bcd28cc39	136	__nop();
intrinseca	0:006bcd28cc39	137	input = input \| _d.read(); // low nibble
intrinseca	0:006bcd28cc39	138	_e = 0;
intrinseca	0:006bcd28cc39	139	return (input);
intrinseca	0:006bcd28cc39	140	}
intrinseca	0:006bcd28cc39	141
intrinseca	0:006bcd28cc39	142	void TextLCD::waitBusy(){
intrinseca	0:006bcd28cc39	143	int input;
intrinseca	0:006bcd28cc39	144	_rw = 1;
intrinseca	0:006bcd28cc39	145	_rs = 0;
intrinseca	0:006bcd28cc39	146	__nop();
intrinseca	0:006bcd28cc39	147	_d.input(); // switch Data port to input
intrinseca	0:006bcd28cc39	148	do{
intrinseca	0:006bcd28cc39	149	_e = 1;
intrinseca	0:006bcd28cc39	150	__nop();
intrinseca	0:006bcd28cc39	151	input = _d.read();
intrinseca	0:006bcd28cc39	152	_e = 0;
intrinseca	0:006bcd28cc39	153	__nop();
intrinseca	0:006bcd28cc39	154	_e = 1;
intrinseca	0:006bcd28cc39	155	__nop();
intrinseca	0:006bcd28cc39	156	_e = 0;
intrinseca	0:006bcd28cc39	157	}while((0x8 & input) == 0x8); // wait until display is ready
intrinseca	0:006bcd28cc39	158	_rw = 0;
intrinseca	0:006bcd28cc39	159	_d.output(); // switch port back to output
intrinseca	0:006bcd28cc39	160	}
intrinseca	0:006bcd28cc39	161
intrinseca	0:006bcd28cc39	162	void TextLCD::writeData(int data) {
intrinseca	0:006bcd28cc39	163	waitBusy();
intrinseca	0:006bcd28cc39	164	_rs = 1;
intrinseca	0:006bcd28cc39	165	writeByte(data);
intrinseca	0:006bcd28cc39	166	}
intrinseca	0:006bcd28cc39	167
intrinseca	0:006bcd28cc39	168
intrinseca	0:006bcd28cc39	169	// set user defined char
intrinseca	0:006bcd28cc39	170	void TextLCD::writeCGRAM(int address, int pattern[8]){
intrinseca	0:006bcd28cc39	171	int i;
intrinseca	0:006bcd28cc39	172	address = address & 0x07; //max 8 char
intrinseca	0:006bcd28cc39	173	for(i=0;i<8;i++){
intrinseca	0:006bcd28cc39	174	waitBusy(); // check if display is ready
intrinseca	0:006bcd28cc39	175	_rs = 0;
intrinseca	0:006bcd28cc39	176	writeByte(0x40 + address * 8 + i);
intrinseca	0:006bcd28cc39	177	writeData(pattern[i]);
intrinseca	0:006bcd28cc39	178	}
intrinseca	0:006bcd28cc39	179	}
intrinseca	0:006bcd28cc39	180
intrinseca	0:006bcd28cc39	181
intrinseca	0:006bcd28cc39	182	int TextLCD::address(int column, int row) {
intrinseca	0:006bcd28cc39	183	switch (_type) {
intrinseca	0:006bcd28cc39	184	case LCD20x4:
intrinseca	0:006bcd28cc39	185	switch (row) {
intrinseca	0:006bcd28cc39	186	case 0:
intrinseca	0:006bcd28cc39	187	return 0x80 + column;
intrinseca	0:006bcd28cc39	188	case 1:
intrinseca	0:006bcd28cc39	189	return 0xc0 + column;
intrinseca	0:006bcd28cc39	190	case 2:
intrinseca	0:006bcd28cc39	191	return 0x94 + column;
intrinseca	0:006bcd28cc39	192	case 3:
intrinseca	0:006bcd28cc39	193	return 0xd4 + column;
intrinseca	0:006bcd28cc39	194	}
intrinseca	0:006bcd28cc39	195	case LCD16x2B:
intrinseca	0:006bcd28cc39	196	return 0x80 + (row * 40) + column;
intrinseca	0:006bcd28cc39	197	case LCD16x2:
intrinseca	0:006bcd28cc39	198	case LCD20x2:
intrinseca	0:006bcd28cc39	199	default:
intrinseca	0:006bcd28cc39	200	return 0x80 + (row * 0x40) + column;
intrinseca	0:006bcd28cc39	201	}
intrinseca	0:006bcd28cc39	202	}
intrinseca	0:006bcd28cc39	203
intrinseca	0:006bcd28cc39	204	int TextLCD::columns() {
intrinseca	0:006bcd28cc39	205	switch (_type) {
intrinseca	0:006bcd28cc39	206	case LCD20x4:
intrinseca	0:006bcd28cc39	207	case LCD20x2:
intrinseca	0:006bcd28cc39	208	return 20;
intrinseca	0:006bcd28cc39	209	case LCD16x2:
intrinseca	0:006bcd28cc39	210	case LCD16x2B:
intrinseca	0:006bcd28cc39	211	default:
intrinseca	0:006bcd28cc39	212	return 16;
intrinseca	0:006bcd28cc39	213	}
intrinseca	0:006bcd28cc39	214	}
intrinseca	0:006bcd28cc39	215
intrinseca	0:006bcd28cc39	216	int TextLCD::rows() {
intrinseca	0:006bcd28cc39	217	switch (_type) {
intrinseca	0:006bcd28cc39	218	case LCD20x4:
intrinseca	0:006bcd28cc39	219	return 4;
intrinseca	0:006bcd28cc39	220	case LCD16x2:
intrinseca	0:006bcd28cc39	221	case LCD16x2B:
intrinseca	0:006bcd28cc39	222	case LCD20x2:
intrinseca	0:006bcd28cc39	223	default:
intrinseca	0:006bcd28cc39	224	return 2;
intrinseca	0:006bcd28cc39	225	}
intrinseca	0:006bcd28cc39	226	}

Repository toolbox

Export to desktop IDE

Repository details

Type:	Library
Created:	21 Mar 2012
Imports:	123
Forks:	0
Commits:	1
Dependents:	3
Dependencies:	0
Followers:	3

TextLCD.cpp@0:006bcd28cc39, 2012-03-21 (annotated)

Who changed what in which revision?

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning