16*2Lcd Display
Dependents: CITY1082-i2c_master
TextLCD.cpp
- Committer:
- simon
- Date:
- 2010-12-04
- Revision:
- 7:44f34c09bd37
- Parent:
- 6:e4cb7ddee0d3
- Child:
- 8:03116f75b66e
File content as of revision 7:44f34c09bd37:
/* mbed TextLCD Library, for a 4-bit LCD based on HD44780 * Copyright (c) 2007-2010, sford, http://mbed.org * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "TextLCD.h" #include "mbed.h" TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type) : _rs(rs), _e(e), _d(d4, d5, d6, d7), _type(type) { _e = 1; _rs = 0; // command mode wait(0.015); // Wait 15ms to ensure powered up // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus) for (int i=0; i<3; i++) { writeByte(0x3); wait(0.00164); // this command takes 1.64ms, so wait for it } writeByte(0x2); // 4-bit mode wait(0.000040f); // most instructions take 40us writeCommand(0x28); // Function set 001 BW N F - - writeCommand(0x0C); writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes cls(); } void TextLCD::character(int column, int row, int c) { int a = address(column, row); writeCommand(a); writeData(c); } void TextLCD::cls() { writeCommand(0x01); // cls, and set cursor to 0 wait(0.00164f); // This command takes 1.64 ms locate(0, 0); } void TextLCD::locate(int column, int row) { _column = column; _row = row; } int TextLCD::_putc(int value) { if (value == '\n') { _column = 0; _row++; if (_row >= rows()) { _row = 0; } } else { character(_column, _row, value); _column++; if (_column >= columns()) { _column = 0; _row++; if (_row >= rows()) { _row = 0; } } } return value; } int TextLCD::_getc() { return -1; } void TextLCD::writeByte(int value) { _d = value >> 4; wait(0.000040f); // most instructions take 40us _e = 0; wait(0.000040f); _e = 1; _d = value >> 0; wait(0.000040f); _e = 0; wait(0.000040f); // most instructions take 40us _e = 1; } void TextLCD::writeCommand(int command) { _rs = 0; writeByte(command); } void TextLCD::writeData(int data) { _rs = 1; writeByte(data); } int TextLCD::address(int column, int row) { switch (_type) { case LCD20x4: switch (row) { case 0: return 0x80 + column; case 1: return 0xc0 + column; case 2: return 0x94 + column; case 3: return 0xd4 + column; } case LCD16x2B: return 0x80 + (row * 40) + column; case LCD16x2: case LCD20x2: default: return 0x80 + (row * 0x40) + column; } } int TextLCD::columns() { switch (_type) { case LCD20x4: case LCD20x2: return 20; case LCD16x2: case LCD16x2B: default: return 16; } } int TextLCD::rows() { switch (_type) { case LCD20x4: return 4; case LCD16x2: case LCD16x2B: case LCD20x2: default: return 2; } }