Revision 1:19be52262a2d, committed 2019-07-26

Comitter:

duchonic

Date:

Fri Jul 26 03:30:12 2019 +0000

Parent:

0:ec079a141883

Commit message:

added lcd shield

Changed in this revision

diff -r ec079a141883 -r 19be52262a2d TextLCD.cpp
--- a/TextLCD.cpp	Fri Jul 27 15:06:59 2012 +0000
+++ b/TextLCD.cpp	Fri Jul 26 03:30:12 2019 +0000
@@ -1,151 +1,159 @@
-/* mbed TextLCD Library
- * Copyright (c) 2007-2009 sford
- * Released under the MIT License: http://mbed.org/license/mit
- */
- 
-#include "TextLCD.h"
-
-#include "mbed.h"
-#include "error.h"
-
-using namespace mbed;
-
-/*
- * useful info found at http://www.a-netz.de/lcd.en.php
+/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
+ * Copyright (c) 2007-2010, sford, http://mbed.org
  *
- *
- * Initialisation
- * ==============
+ * 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:
  *
- * 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
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
  *
- * 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
+ * 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.
  */
 
-TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, 
-	PinName d2, PinName d3, int columns, int rows) : _rw(rw), _rs(rs), 
-	_e(e), _d(d0, d1, d2, d3), _columns(columns), _rows(rows) {
+#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) {
 
-//	_rows = 2;
-//	_columns = 16;
-	// Mon, 27 Apr 2009 23:32:34 +0200
-	// Kevin Konradt:
-	// When using a LCD with 1 row x 16 characters
-	// instead of 2x16, try changing _columns to 8.
-	// (display seems to split the 16 characters into 
-	// 2 virtual rows with 8 characters each.)
+    _e  = 1;
+    _rs = 0;            // command mode
+
+    wait(0.015);        // Wait 15ms to ensure powered up
 
-	_rw = 0;
-	_e  = 1;
-	_rs = 0; // command mode
+    // 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
 
-	// 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++) {
-		writeNibble(0x3);
-		wait(0.00164);      // this command takes 1.64ms, so wait for it
-	}
-	writeNibble(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();
+    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') {
-		newline();
-	} else {
-		writeData(value);
-	}
-	return 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 0;
-}
-
-void TextLCD::newline() {
-	_column = 0;
-	_row++;
-	if(_row >= _rows) {
-		_row = 0;
-	}
-	locate(_column, _row); 
-}
-
-void TextLCD::locate(int column, int row) {
-	if(column < 0 || column >= _columns || row < 0 || row >= _rows) {
-		error("locate(%d,%d) out of range on %dx%d display", column, row, _columns, _rows);
-		return;
-	}
-	
-	_row = row;
-  	_column = column;
-  	int address = 0x80 + (_row * 40) + _column; // memory starts at 0x80, and is 40 chars long per row
-  	writeCommand(address);            
-}
-
-void TextLCD::cls() {
-	writeCommand(0x01); // Clear Display
-	wait(0.00164f);		// This command takes 1.64 ms
-  	locate(0, 0);
-}
-
-void TextLCD::reset() {
-	cls();
-}
-
-void TextLCD::clock() {
-	wait(0.000040f);
-	_e = 0;
-	wait(0.000040f);  // most instructions take 40us
-	_e = 1;	
-}
-
-void TextLCD::writeNibble(int value) {
-	_d = value;
-	clock();
+    return -1;
 }
 
 void TextLCD::writeByte(int value) {
-	writeNibble(value >> 4);
-	writeNibble(value >> 0);
+    _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);
+    _rs = 0;
+    writeByte(command);
 }
 
 void TextLCD::writeData(int data) {
-	_rs = 1;
-	writeByte(data);
-	_column++;
-	if(_column >= _columns) {
-		newline();
-	} 
+    _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;
+    }
+}

diff -r ec079a141883 -r 19be52262a2d TextLCD.h
--- a/TextLCD.h	Fri Jul 27 15:06:59 2012 +0000
+++ b/TextLCD.h	Fri Jul 26 03:30:12 2019 +0000
@@ -1,109 +1,111 @@
-/* mbed TextLCD Library
- * Copyright (c) 2007-2009 sford
- * Released under the MIT License: http://mbed.org/license/mit
+/* 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.
  */
- 
+
 #ifndef MBED_TEXTLCD_H
 #define MBED_TEXTLCD_H
 
-#include "Stream.h"
-#include "DigitalOut.h"
-#include "BusOut.h"
-
-namespace mbed {
+#include "mbed.h"
 
-/* Class: TextLCD
- * A 16x2 Text LCD controller
+/**  A TextLCD interface for driving 4-bit HD44780-based LCDs
  *
- * Allows you to print to a Text LCD screen, and locate/cls. Could be
- * turned in to a more generic libray.
+ * Currently supports 16x2, 20x2 and 20x4 panels
  *
- * If you are connecting multiple displays, you can connect them all in
- * parallel except for the enable (e) pin, which must be unique for each
- * display.
- *
- * Example:
- * > #include "mbed.h"
- * > #include "TextLCD.h"
- * >
- * > TextLCD lcd(p24, p25, p26, p27, p28, p29, p30); // rs, rw, e, d0, d1, d2, d3
- * >
- * > int main() {
- * >     lcd.printf("Hello World!");
- * > }
+ * @code
+ * #include "mbed.h"
+ * #include "TextLCD.h"
+ * 
+ * TextLCD lcd(p10, p12, p15, p16, p29, p30); // rs, e, d4-d7
+ * 
+ * int main() {
+ *     lcd.printf("Hello World!\n");
+ * }
+ * @endcode
  */
 class TextLCD : public Stream {
+public:
 
-public:
-    /* Constructor: TextLCD
-     * Create a TextLCD object, connected to the specified pins
-     *
-     * All signals must be connected to DigitalIn compatible pins. 
+    /** 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 interface
      *
-     * Variables:
-     *  rs -  Used to specify data or command
-     *  rw - Used to determine read or write
-     *  e - enable
-     *  d0..d3 - The data lines
+     * @param rs    Instruction/data control line
+     * @param e     Enable line (clock)
+     * @param d4-d7 Data lines for using as a 4-bit interface
+     * @param type  Sets the panel size/addressing mode (default = LCD16x2)
      */
-	TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, 
-		PinName d2, PinName d3, int columns = 16, int rows = 2);
+    TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2);
 
-#if 0 // Inhereted from Stream, for documentation only
-    /* Function: putc
-     *  Write a character
+#if DOXYGEN_ONLY
+    /** Write a character to the LCD
      *
-     * Variables:
-     *  c - The character to write to the serial port
+     * @param c The character to write to the display
      */
     int putc(int c);
 
-    /* Function: printf
-     *  Write a formated string
+    /** Write a formated string to the LCD
      *
-     * Variables:
-     *  format - A printf-style format string, followed by the
-     *      variables to use in formating the string.
+     * @param format A printf-style format string, followed by the
+     *               variables to use in formating the string.
      */
     int printf(const char* format, ...);
 #endif
-        
-    /* Function: locate
-     * Locate to a certian position
+
+    /** Locate to a screen column and row
      *
-     * Variables:
-     *  column - the column to locate to, from 0..15
-     *  row - the row to locate to, from 0..1
+     * @param column  The horizontal position from the left, indexed from 0
+     * @param row     The vertical position from the top, indexed from 0
      */
-	virtual void locate(int column, int row);
-    
-    /* Function: cls
-     * Clear the screen, and locate to 0,0
-     */
-	virtual void cls();	
-    
-	virtual void reset();
-		
+    void locate(int column, int row);
+
+    /** Clear the screen and locate to 0,0 */
+    void cls();
+
+    int rows();
+    int columns();
+
 protected:
 
-	void clock();
-	void writeData(int data);
-	void writeCommand(int command);
-	void writeByte(int value);
-	void writeNibble(int value);
-	virtual int _putc(int c);		
-	virtual int _getc();
-	virtual void newline();				
-			
-	int _row;
-	int _column;	
-	DigitalOut _rw, _rs, _e;
-	BusOut _d;
-	int _columns;
-	int _rows;
+    // 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);
+
+    DigitalOut _rs, _e;
+    BusOut _d;
+    LCDType _type;
+
+    int _column;
+    int _row;
 };
 
-}
-
 #endif