TextLCD
Revision 1:ac48b187213c, committed 2010-05-27
- Comitter:
- simon
- Date:
- Thu May 27 13:44:15 2010 +0000
- Parent:
- 0:edfb85c53631
- Child:
- 2:227356c7d12c
- Commit message:
Changed in this revision
--- a/TextDisplay.cpp Sat May 22 18:18:19 2010 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,75 +0,0 @@ -/* mbed TextDisplay Library Base Class - * 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. - */ - -#include "TextDisplay.h" - -TextDisplay::TextDisplay() { - _row = 0; - _column = 0; -} - -int TextDisplay::_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; -} - -// a basic cls implementation, that should generally be overwritten -// with a more efficient implementation -void TextDisplay::cls() { - locate(0, 0); - for(int i=0; i<columns()*rows(); i++) { - putc(' '); - } -} - -void TextDisplay::locate(int column, int row) { - _column = column; - _row = row; -} - -int TextDisplay::_getc() { - return -1; -} - -void TextDisplay::foreground(int colour) { - _foreground = colour; -} - -void TextDisplay::background(int colour) { - _background = colour; -}
--- a/TextDisplay.h Sat May 22 18:18:19 2010 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,71 +0,0 @@ -/* mbed TextDisplay Library Base Class - * 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. - * - * A common base class for driving Text displays, providing useful functionality - * that can be shared by all text lcds. To port a new display, derive from this - * class and implement the constructor (setup the display), character (put a - * character at a location), rows and columns (number of rows/cols) functions. - * Everything else (locate, printf, putc, cls) will come for free - * - * The model is the display will wrap at the right and bottom, so you can - * keep writing and will always get valid characters. The location is - * maintained internally to the class to make this easier - */ - -#ifndef MBED_TEXTDISPLAY_H -#define MBED_TEXTDISPLAY_H - -#include "mbed.h" - -class TextDisplay : public Stream { -public: - - // functions to be implementated in the derived class - TextDisplay(); - virtual void character(int column, int row, int c) = 0; - virtual int rows() = 0; - virtual int columns() = 0; - - // functions that come for free, but can be overwritten - virtual void cls(); - virtual void locate(int column, int row); - virtual void foreground(int colour); - virtual void background(int colour); - - // other stdio-type functions - // putc() inherited from Stream - // printf() is inherited from Stream - -protected: - - virtual int _putc(int value); - virtual int _getc(); - - // character location - short _column; - short _row; - - // colours - int _foreground; - int _background; -}; - -#endif
--- a/TextLCD.cpp Sat May 22 18:18:19 2010 +0000 +++ b/TextLCD.cpp Thu May 27 13:44:15 2010 +0000 @@ -1,115 +1,186 @@ -/* mbed TextLCD Library, 4-bit 2x16 - * 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. - */ - -#include "TextLCD.h" -#include "mbed.h" - -/* - * useful info found at http://www.a-netz.de/lcd.en.php - * - * Initialisation - * ============== - * - * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state - * - * - wait approximately 15 ms so the display is ready to execute commands - * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now). - * - 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. - * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now. - * - Execute the "clear display" command - * - * Timing - * ====== - * - * Nearly all commands transmitted to the display need 40us for execution. - * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position" - * These commands need 1.64ms for execution. These timings are valid for all displays working with an - * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you - * can use the busy flag to test if the display is ready to accept the next command. - * - * _e is kept high apart from calling clock - * _rw is kept 0 (write) apart from actions that uyse it differently - * _rs is set by the data/command writes - */ - -TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, - PinName d2, PinName d3) : _rw(rw), _rs(rs), - _e(e), _d(d0, d1, d2, d3) { - - _rw = 0; - _e = 1; - _rs = 0; // command mode - - // Should theoretically wait 15ms, but most things will be powered up pre-reset - // so i'll disable that for the minute. If implemented, could wait 15ms post reset - // instead - // wait(0.015); - - // 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 - - 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 address = 0x80 + (row * 40) + column; // memory starts at 0x80, and is 40 chars long per row - writeCommand(address); - writeData(c); -} - -int TextLCD::columns() { - return 16; -} - -int TextLCD::rows() { - return 2; -} - -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); -} +/* mbed TextLCD 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. + */ + +#include "TextLCD.h" +#include "mbed.h" + +/* useful info found at http://www.a-netz.de/lcd.en.php + * + * Initialisation + * ============== + * + * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state + * + * - wait approximately 15 ms so the display is ready to execute commands + * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now). + * - 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. + * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now. + * - Execute the "clear display" command + * + * Timing + * ====== + * + * Nearly all commands transmitted to the display need 40us for execution. + * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position" + * These commands need 1.64ms for execution. These timings are valid for all displays working with an + * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you + * can use the busy flag to test if the display is ready to accept the next command. + * + * _e is kept high apart from calling clock + * _rw is kept 0 (write) apart from actions that uyse it differently + * _rs is set by the data/command writes + */ + +TextLCD::TextLCD(PinName rs, PinName e, PinName d0, PinName d1, + PinName d2, PinName d3, LCDType type) : _rs(rs), + _e(e), _d(d0, d1, d2, d3), + _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 * 0x40) + column; + case LCD16x2: + case LCD20x2: + default: + return 0x80 + (row * 40) + 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; + } +}
--- a/TextLCD.h Sat May 22 18:18:19 2010 +0000 +++ b/TextLCD.h Thu May 27 13:44:15 2010 +0000 @@ -1,48 +1,71 @@ -/* mbed TextLCD Library, for a 4-bit 2x16 LCD - * 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. - */ - -#include "TextDisplay.h" - -#ifndef MBED_TEXTLCD_H -#define MBED_TEXTLCD_H - -class TextLCD : public TextDisplay { -public: - - TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, PinName d2, PinName d3); - virtual void character(int column, int row, int c); - virtual int rows(); - virtual int columns(); - - // locate, cls, putc, printf come from derived classes - -protected: - - void writeByte(int value); - void writeCommand(int command); - void writeData(int data); - - DigitalOut _rw, _rs, _e; - BusOut _d; -}; - -#endif +/* mbed TextLCD 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. + */ + +#ifndef MBED_TEXTLCD_H +#define MBED_TEXTLCD_H + +#include "mbed.h" +class TextLCD : public Stream { +public: + + // the different LCDs and addressing modes + /** Select the type of LCD */ + enum LCDType { + LCD16x2 + , LCD16x2B + , LCD20x2 + , LCD20x4 + }; + + TextLCD(PinName rs, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, LCDType type = LCD16x2); + // int putc(int c) inherited from Stream + // int printf(...) inherited from Stream + void character(int column, int row, int c); + void locate(int column, int row); + void cls(); + + int rows(); + int columns(); + + +protected: + + // Stream implementation functions + virtual int _putc(int value); + virtual int _getc(); + + // internal tx functions + void writeByte(int value); + void writeCommand(int command); + void writeData(int data); + int address(int column, int row); + + DigitalOut _rs, _e; + BusOut _d; + LCDType _type; + + // current row/column + int _column; + int _row; +}; + +#endif
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Thu May 27 13:44:15 2010 +0000 @@ -0,0 +1,43 @@ +// Write to all HD44780 TextLCD RAM locations, sford +// +// A quick hack to write to all the display RAM locations +// in an HD44780 display, to identify which location maps +// to which character. +// +// Instructions: +// - Change TextLCD pinout as appropriate so it works +// - Run, and it should fill the screen with characters +// - Identify what characters are at the start of each row +// +// To determine what address each line starts at, you subtract the +// ascii code for '0'(48) from the character at the start of each line +// - see http://www.asciitable.com/ +// +// e.g. +// +----------------+ +// |0123456789:;<=>?| first char = '0' (48) +// |XYZ.... | first char = 'X' (88) +// +----------------+ +// +// So in this case, the RAM offsets are 0 and 40 + +#include "mbed.h" +#include "TextLCD.h" +DigitalOut zero(p11); +TextLCD lcd(p10, p12, p15, p16, p29, p30, TextLCD::LCD16x2B); + +int main() { + lcd.printf("hithere"); + wait(1); + lcd.putc('i'); + wait(1); + lcd.cls(); + wait(1); + lcd.locate(4, 1); + wait(1); + lcd.printf("jdlkjfksj"); + for(int i=0; i<30; i++) { + lcd.putc('A' + i); + wait(0.3); + } +}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Thu May 27 13:44:15 2010 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/e6be4cd80aad