2bk0118_GPS_Test02

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Takeuchi Kouichi / Mbed 2 deprecated 2bk0118_GPS_Test02

TextLCD0420.cpp@0:1d5d3506a5ea, 2011-01-30 (annotated)

Committer:: takeuchi
Date:: Sun Jan 30 07:24:25 2011 +0000
Revision:: 0:1d5d3506a5ea

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User	Revision	Line number	New contents of line
takeuchi	0:1d5d3506a5ea	1	/* mbed TextLCD Library
takeuchi	0:1d5d3506a5ea	2	* Copyright (c) 2007-2009 sford
takeuchi	0:1d5d3506a5ea	3	* Released under the MIT License: http://mbed.org/license/mit
takeuchi	0:1d5d3506a5ea	4	*/
takeuchi	0:1d5d3506a5ea	5	// for 04row*20line LCD
takeuchi	0:1d5d3506a5ea	6
takeuchi	0:1d5d3506a5ea	7	#include "TextLCD0420.h"
takeuchi	0:1d5d3506a5ea	8
takeuchi	0:1d5d3506a5ea	9	#include "mbed.h"
takeuchi	0:1d5d3506a5ea	10	#include "error.h"
takeuchi	0:1d5d3506a5ea	11
takeuchi	0:1d5d3506a5ea	12	using namespace mbed;
takeuchi	0:1d5d3506a5ea	13
takeuchi	0:1d5d3506a5ea	14	/*
takeuchi	0:1d5d3506a5ea	15	* useful info found at http://www.a-netz.de/lcd.en.php
takeuchi	0:1d5d3506a5ea	16	*
takeuchi	0:1d5d3506a5ea	17	*
takeuchi	0:1d5d3506a5ea	18	* Initialisation
takeuchi	0:1d5d3506a5ea	19	* ==============
takeuchi	0:1d5d3506a5ea	20	*
takeuchi	0:1d5d3506a5ea	21	* After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state
takeuchi	0:1d5d3506a5ea	22	*
takeuchi	0:1d5d3506a5ea	23	* - wait approximately 15 ms so the display is ready to execute commands
takeuchi	0:1d5d3506a5ea	24	* - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now).
takeuchi	0:1d5d3506a5ea	25	* - 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.
takeuchi	0:1d5d3506a5ea	26	* - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now.
takeuchi	0:1d5d3506a5ea	27	* - Execute the "clear display" command
takeuchi	0:1d5d3506a5ea	28	*
takeuchi	0:1d5d3506a5ea	29	* Timing
takeuchi	0:1d5d3506a5ea	30	* ======
takeuchi	0:1d5d3506a5ea	31	*
takeuchi	0:1d5d3506a5ea	32	* Nearly all commands transmitted to the display need 40us for execution.
takeuchi	0:1d5d3506a5ea	33	* Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position"
takeuchi	0:1d5d3506a5ea	34	* These commands need 1.64ms for execution. These timings are valid for all displays working with an
takeuchi	0:1d5d3506a5ea	35	* internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you
takeuchi	0:1d5d3506a5ea	36	* can use the busy flag to test if the display is ready to accept the next command.
takeuchi	0:1d5d3506a5ea	37	*
takeuchi	0:1d5d3506a5ea	38	* _e is kept high apart from calling clock
takeuchi	0:1d5d3506a5ea	39	* _rw is kept 0 (write) apart from actions that uyse it differently
takeuchi	0:1d5d3506a5ea	40	* _rs is set by the data/command writes
takeuchi	0:1d5d3506a5ea	41	*/
takeuchi	0:1d5d3506a5ea	42
takeuchi	0:1d5d3506a5ea	43	TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1,
takeuchi	0:1d5d3506a5ea	44	PinName d2, PinName d3, int columns, int rows) : _rw(rw), _rs(rs),
takeuchi	0:1d5d3506a5ea	45	_e(e), _d(d0, d1, d2, d3), _columns(columns), _rows(rows) {
takeuchi	0:1d5d3506a5ea	46
takeuchi	0:1d5d3506a5ea	47
takeuchi	0:1d5d3506a5ea	48	// Mon, 27 Apr 2009 23:32:34 +0200
takeuchi	0:1d5d3506a5ea	49	// Kevin Konradt:
takeuchi	0:1d5d3506a5ea	50	// When using a LCD with 1 row x 16 characters
takeuchi	0:1d5d3506a5ea	51	// instead of 2x16, try changing _columns to 8.
takeuchi	0:1d5d3506a5ea	52	// (display seems to split the 16 characters into
takeuchi	0:1d5d3506a5ea	53	// 2 virtual rows with 8 characters each.)
takeuchi	0:1d5d3506a5ea	54
takeuchi	0:1d5d3506a5ea	55	_rw = 0;
takeuchi	0:1d5d3506a5ea	56	_e = 1;
takeuchi	0:1d5d3506a5ea	57	_rs = 0; // command mode
takeuchi	0:1d5d3506a5ea	58
takeuchi	0:1d5d3506a5ea	59	// Should theoretically wait 15ms, but most things will be powered up pre-reset
takeuchi	0:1d5d3506a5ea	60	// so i'll disable that for the minute. If implemented, could wait 15ms post reset
takeuchi	0:1d5d3506a5ea	61	// instead
takeuchi	0:1d5d3506a5ea	62	// wait(0.015);
takeuchi	0:1d5d3506a5ea	63
takeuchi	0:1d5d3506a5ea	64	// send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
takeuchi	0:1d5d3506a5ea	65	for(int i=0; i<3; i++) {
takeuchi	0:1d5d3506a5ea	66	writeNibble(0x3);
takeuchi	0:1d5d3506a5ea	67	wait(0.00164); // this command takes 1.64ms, so wait for it
takeuchi	0:1d5d3506a5ea	68	}
takeuchi	0:1d5d3506a5ea	69	writeNibble(0x2); // 4-bit mode
takeuchi	0:1d5d3506a5ea	70
takeuchi	0:1d5d3506a5ea	71	writeCommand(0x28); // Function set 001 BW N F - -
takeuchi	0:1d5d3506a5ea	72	writeCommand(0x0C);
takeuchi	0:1d5d3506a5ea	73	writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
takeuchi	0:1d5d3506a5ea	74
takeuchi	0:1d5d3506a5ea	75	cls();
takeuchi	0:1d5d3506a5ea	76	}
takeuchi	0:1d5d3506a5ea	77
takeuchi	0:1d5d3506a5ea	78	int TextLCD::_putc(int value) {
takeuchi	0:1d5d3506a5ea	79	if(value == '\n') {
takeuchi	0:1d5d3506a5ea	80	newline();
takeuchi	0:1d5d3506a5ea	81	} else {
takeuchi	0:1d5d3506a5ea	82	writeData(value);
takeuchi	0:1d5d3506a5ea	83	}
takeuchi	0:1d5d3506a5ea	84	return value;
takeuchi	0:1d5d3506a5ea	85	}
takeuchi	0:1d5d3506a5ea	86
takeuchi	0:1d5d3506a5ea	87	int TextLCD::_getc() {
takeuchi	0:1d5d3506a5ea	88	return 0;
takeuchi	0:1d5d3506a5ea	89	}
takeuchi	0:1d5d3506a5ea	90
takeuchi	0:1d5d3506a5ea	91	void TextLCD::newline() {
takeuchi	0:1d5d3506a5ea	92	_column = 0;
takeuchi	0:1d5d3506a5ea	93	_row++;
takeuchi	0:1d5d3506a5ea	94	if(_row >= _rows) {
takeuchi	0:1d5d3506a5ea	95	_row = 0;
takeuchi	0:1d5d3506a5ea	96	}
takeuchi	0:1d5d3506a5ea	97	locate(_column, _row);
takeuchi	0:1d5d3506a5ea	98	}
takeuchi	0:1d5d3506a5ea	99
takeuchi	0:1d5d3506a5ea	100	void TextLCD::locate(int column, int row) {
takeuchi	0:1d5d3506a5ea	101	int address;
takeuchi	0:1d5d3506a5ea	102	if(column < 0 \|\| column >= _columns \|\| row < 0 \|\| row >= _rows) {
takeuchi	0:1d5d3506a5ea	103	error("locate(%d,%d) out of range on %dx%d display", column, row, _columns, _rows);
takeuchi	0:1d5d3506a5ea	104	return;
takeuchi	0:1d5d3506a5ea	105	}
takeuchi	0:1d5d3506a5ea	106
takeuchi	0:1d5d3506a5ea	107	_row = row;
takeuchi	0:1d5d3506a5ea	108	_column = column;
takeuchi	0:1d5d3506a5ea	109	// 0220 => int address = 0x80 + (_row 40) + _column; // memory starts at 0x80, and is 40 chars long per row
takeuchi	0:1d5d3506a5ea	110
takeuchi	0:1d5d3506a5ea	111
takeuchi	0:1d5d3506a5ea	112	if(_row == 0 ){
takeuchi	0:1d5d3506a5ea	113	address = 0x80+_column;
takeuchi	0:1d5d3506a5ea	114	}
takeuchi	0:1d5d3506a5ea	115	else if(_row == 1 ){
takeuchi	0:1d5d3506a5ea	116	address = 0x80+ (0x40) + _column;
takeuchi	0:1d5d3506a5ea	117	}
takeuchi	0:1d5d3506a5ea	118	else if(_row == 2){
takeuchi	0:1d5d3506a5ea	119	address = 0x80+(0x14)+_column;
takeuchi	0:1d5d3506a5ea	120	}
takeuchi	0:1d5d3506a5ea	121	else if(_row == 3){
takeuchi	0:1d5d3506a5ea	122	address = 0x80+(0x54)+_column;
takeuchi	0:1d5d3506a5ea	123	}
takeuchi	0:1d5d3506a5ea	124
takeuchi	0:1d5d3506a5ea	125	writeCommand(address);
takeuchi	0:1d5d3506a5ea	126	}
takeuchi	0:1d5d3506a5ea	127
takeuchi	0:1d5d3506a5ea	128	void TextLCD::cls() {
takeuchi	0:1d5d3506a5ea	129	writeCommand(0x01); // Clear Display
takeuchi	0:1d5d3506a5ea	130	wait(0.00164f); // This command takes 1.64 ms
takeuchi	0:1d5d3506a5ea	131	locate(0, 0);
takeuchi	0:1d5d3506a5ea	132	}
takeuchi	0:1d5d3506a5ea	133
takeuchi	0:1d5d3506a5ea	134	void TextLCD::reset() {
takeuchi	0:1d5d3506a5ea	135	cls();
takeuchi	0:1d5d3506a5ea	136	}
takeuchi	0:1d5d3506a5ea	137
takeuchi	0:1d5d3506a5ea	138	void TextLCD::clock() {
takeuchi	0:1d5d3506a5ea	139	wait(0.000040f);
takeuchi	0:1d5d3506a5ea	140	_e = 0;
takeuchi	0:1d5d3506a5ea	141	wait(0.000040f); // most instructions take 40us
takeuchi	0:1d5d3506a5ea	142	_e = 1;
takeuchi	0:1d5d3506a5ea	143	}
takeuchi	0:1d5d3506a5ea	144
takeuchi	0:1d5d3506a5ea	145	void TextLCD::writeNibble(int value) {
takeuchi	0:1d5d3506a5ea	146	_d = value;
takeuchi	0:1d5d3506a5ea	147	clock();
takeuchi	0:1d5d3506a5ea	148	}
takeuchi	0:1d5d3506a5ea	149
takeuchi	0:1d5d3506a5ea	150	void TextLCD::writeByte(int value) {
takeuchi	0:1d5d3506a5ea	151	writeNibble(value >> 4);
takeuchi	0:1d5d3506a5ea	152	writeNibble(value >> 0);
takeuchi	0:1d5d3506a5ea	153	}
takeuchi	0:1d5d3506a5ea	154
takeuchi	0:1d5d3506a5ea	155	void TextLCD::writeCommand(int command) {
takeuchi	0:1d5d3506a5ea	156	_rs = 0;
takeuchi	0:1d5d3506a5ea	157	writeByte(command);
takeuchi	0:1d5d3506a5ea	158	}
takeuchi	0:1d5d3506a5ea	159
takeuchi	0:1d5d3506a5ea	160	void TextLCD::writeData(int data) {
takeuchi	0:1d5d3506a5ea	161	_rs = 1;
takeuchi	0:1d5d3506a5ea	162	writeByte(data);
takeuchi	0:1d5d3506a5ea	163	_column++;
takeuchi	0:1d5d3506a5ea	164	if(_column >= _columns) {
takeuchi	0:1d5d3506a5ea	165	newline();
takeuchi	0:1d5d3506a5ea	166	}
takeuchi	0:1d5d3506a5ea	167	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	30 Jan 2011
Imports:	24
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	1

TextLCD0420.cpp@0:1d5d3506a5ea, 2011-01-30 (annotated)

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