http://mbed.org/users/shintamainjp/notebook/textlcd_sr4_en/
Dependents: TextLCD_SR4_TestProgram ServoInterfaceBoardExample1
Revision 2:e768257aba09, committed 2010-10-25
- Comitter:
- shintamainjp
- Date:
- Mon Oct 25 22:41:56 2010 +0000
- Parent:
- 1:7c375c1ac22c
- Commit message:
Changed in this revision
diff -r 7c375c1ac22c -r e768257aba09 TextLCD_SR4.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/TextLCD_SR4.cpp Mon Oct 25 22:41:56 2010 +0000 @@ -0,0 +1,179 @@ +/* mbed TextLCD_SR4 Library, for a 4-bit LCD based on HD44780 + * Copyright (c) 2007-2010, sford + * + * 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. + */ + +/* + * Modified for http://mbed.org/users/shintamainjp/notebook/textlcd_sr4_en/ + * Shinichiro Nakamura + */ + +#include "TextLCD_SR4.h" +#include "mbed.h" + +TextLCD_SR4::TextLCD_SR4(PinName rs, PinName e, PinName dat, PinName clk, LCDType type) + : _rs(rs), _e(e), _dat(dat), _clk(clk), _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_SR4::character(int column, int row, int c) { + int a = address(column, row); + writeCommand(a); + writeData(c); +} + +void TextLCD_SR4::cls() { + writeCommand(0x01); // cls, and set cursor to 0 + wait(0.00164f); // This command takes 1.64 ms + locate(0, 0); +} + +void TextLCD_SR4::locate(int column, int row) { + _column = column; + _row = row; +} + +int TextLCD_SR4::_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_SR4::_getc() { + return -1; +} + +void TextLCD_SR4::writeByte(int value) { + writeToShiftRegister(value << 0); + wait(0.000040f); // most instructions take 40us + _e = 0; + wait(0.000040f); + _e = 1; + writeToShiftRegister(value << 4); + wait(0.000040f); + _e = 0; + wait(0.000040f); // most instructions take 40us + _e = 1; +} + +void TextLCD_SR4::writeToShiftRegister(int value) { + /* + * MSB first. + */ + for (int i = 0; i < 8; i++) { + if (value & (1 << (7 - i))) { + _dat = 1; + } else { + _dat = 0; + } + _clk = 1; + wait_us(1); + _clk = 0; + wait_us(1); + } +} + +void TextLCD_SR4::writeCommand(int command) { + _rs = 0; + writeByte(command); +} + +void TextLCD_SR4::writeData(int data) { + _rs = 1; + writeByte(data); +} + +int TextLCD_SR4::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_SR4::columns() { + switch (_type) { + case LCD20x4: + case LCD20x2: + return 20; + case LCD16x2: + case LCD16x2B: + default: + return 16; + } +} + +int TextLCD_SR4::rows() { + switch (_type) { + case LCD20x4: + return 4; + case LCD16x2: + case LCD16x2B: + case LCD20x2: + default: + return 2; + } +}
diff -r 7c375c1ac22c -r e768257aba09 TextLCD_SR4.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/TextLCD_SR4.h Mon Oct 25 22:41:56 2010 +0000 @@ -0,0 +1,96 @@ + +#ifndef _TEXT_LCD_SR4_H +#define _TEXT_LCD_SR4_H + +#include "mbed.h" + +/* + * Modified for http://mbed.org/users/shintamainjp/notebook/textlcd_sr4_en/ + * Shinichiro Nakamura + */ + +/** + * A TextLCD_SR4 interface for driving 4-bit HD44780-based LCDs with shift register. + * + * Currently supports 16x2, 20x2 and 20x4 panels + * + * @code + * #include "mbed.h" + * #include "TextLCD_SR4.h" + * + * TextLCD_SR4 lcd(p29, p30, p28, p27); // rs, e, dat, clk + * + * int main() { + * lcd.printf("Hello World!\n"); + * } + * @endcode + */ +class TextLCD_SR4 : public Stream { +public: + /** LCD panel format */ + enum LCDType { + LCD16x2 /**< 16x2 LCD panel (default) */ + , LCD16x2B /**< 16x2 LCD panel alternate addressing */ + , LCD20x2 /**< 20x2 LCD panel */ + , LCD20x4 /**< 20x4 LCD panel */ + }; + + /** Create a TextLCD_SR4 interface + * + * @param rs Instruction/data control line + * @param e Enable line (clock) + * @param dat Data line + * @param clk Clock line + */ + TextLCD_SR4(PinName rs, PinName e, PinName dat, PinName clk, LCDType type = LCD16x2); + +#if DOXYGEN_ONLY + /** Write a character to the LCD + * + * @param c The character to write to the display + */ + int putc(int c); + + /** Write a formated string to the LCD + * + * @param format A printf-style format string, followed by the + * variables to use in formating the string. + */ + int printf(const char* format, ...); +#endif + + /** Locate to a screen column and row + * + * @param column The horizontal position from the left, indexed from 0 + * @param row The vertical position from the top, indexed from 0 + */ + void locate(int column, int row); + + /** Clear the screen and locate to 0,0 */ + void cls(); + + int rows(); + int columns(); + +protected: + + // Stream implementation functions + virtual int _putc(int value); + virtual int _getc(); + + int address(int column, int row); + void character(int column, int row, int c); + void writeByte(int value); + void writeCommand(int command); + void writeData(int data); + + void writeToShiftRegister(int value); + + DigitalOut _rs, _e, _dat, _clk; + LCDType _type; + + int _column; + int _row; +}; + +#endif
diff -r 7c375c1ac22c -r e768257aba09 main.cpp --- a/main.cpp Mon Oct 25 22:41:04 2010 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,17 +0,0 @@ -#include "mbed.h" -#include "TextLCD_SR4.h" - -TextLCD_SR4 lcd(p29, p30, p28, p27); - -int main() { - lcd.locate(0, 0); - lcd.printf(" TextLCD_SR4 "); - lcd.locate(0, 1); - lcd.printf(" Library test "); - wait(5); - int n = 0; - while (1) { - lcd.locate(0, 1); - lcd.printf("count:%10d", n++); - } -}
diff -r 7c375c1ac22c -r e768257aba09 mbed.bld --- a/mbed.bld Mon Oct 25 22:41:04 2010 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1 +0,0 @@ -http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e