The start of a generic Text Display library to drive multiple types of text display in the same way

Dependencies:   mbed

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API Documentation at this revision

Comitter:
simon
Date:
Wed Nov 25 00:01:31 2009 +0000
Commit message:

Changed in this revision

Terminal.cpp Show annotated file Show diff for this revision Revisions of this file
Terminal.h Show annotated file Show diff for this revision Revisions of this file
TextDisplay.cpp Show annotated file Show diff for this revision Revisions of this file
TextDisplay.h Show annotated file Show diff for this revision Revisions of this file
TextDisplays.h Show annotated file Show diff for this revision Revisions of this file
TextLCD.cpp Show annotated file Show diff for this revision Revisions of this file
TextLCD.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Terminal.cpp	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,73 @@
+/* mbed Terminal TextDisplay Library
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+ 
+#include "Terminal.h"
+
+#include "mbed.h"
+
+Terminal::Terminal(PinName tx, PinName rx) : _serial(tx, rx) {
+    cls();
+}
+
+void Terminal::character(int column, int row, int c) {
+    // Cursor Home	<ESC>[{ROW};{COLUMN}H 
+	_serial.printf("\033[%d;%dH%c", row + 1, column + 1, c);
+}
+
+int Terminal::columns() {
+    return 80;
+}
+
+int Terminal::rows() { 
+    return 35; 
+}
+
+void Terminal::cls() {
+    _serial.printf("\033[2J");
+}
+
+void Terminal::foreground(int colour) {
+
+	/* Set Attribute Mode	<ESC>[{n}m
+	 * - Sets display attribute settings. The following lists standard attributes:
+	 * 
+   	 * Foreground Colours
+   	 * 30	Black
+   	 * 31	Red
+   	 * 32	Green
+   	 * 33	Yellow
+   	 * 34	Blue
+   	 * 35	Magenta
+   	 * 36	Cyan
+   	 * 37	White
+   	 */
+   	 int r = (colour >> 23) & 1;
+   	 int g = (colour >> 15) & 1;
+   	 int b = (colour >> 7) & 1;
+   	 int bgr = (b << 2) | (g << 1) | (r << 0);
+   	 int c = 30 + bgr;
+    _serial.printf("\033[%dm", c);
+}
+
+void Terminal::background(int colour) {
+	  
+   	 /* Background Colours
+   	 * 40	Black
+   	 * 41	Red
+   	 * 42	Green
+   	 * 43	Yellow
+   	 * 44	Blue
+   	 * 45	Magenta
+   	 * 46	Cyan
+   	 * 47	White
+	 */
+   	 int r = (colour >> 23) & 1;
+   	 int g = (colour >> 15) & 1;
+   	 int b = (colour >> 7) & 1;
+   	 int bgr = (b << 2) | (g << 1) | (r << 0);
+   	 int c = 40 + bgr;
+     _serial.printf("\033[%dm", c);
+}
+ 
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Terminal.h	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,33 @@
+/* mbed Terminal TextDisplay Library
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ *
+ * Implementation of a TextDisplay using a VT100 Terminal and 
+ * escape codes (e.g. Teraterm, Hyperterminal)
+ */
+
+#include "TextDisplay.h"
+
+#ifndef MBED_TERMINAL_H
+#define MBED_TERMINAL_H
+
+class Terminal : public TextDisplay {
+public:
+
+    Terminal(PinName tx, PinName rx);
+
+    virtual void character(int column, int row, int c);
+    virtual int rows(); 
+    virtual int columns();  
+
+	virtual void cls();
+    virtual void foreground(int colour);
+    virtual void background(int colour);
+
+protected:
+
+    Serial _serial;
+    
+};
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextDisplay.cpp	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,57 @@
+/* mbed TextDisplay Display Library Base Class
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+ 
+#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;
+}
+
+// crude cls implementation, should generally be overwritten in derived class
+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;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextDisplay.h	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,52 @@
+/* mbed TextDisplay Library Base Class
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ *
+ * A common base class for Text displays
+ * 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 easy
+ */
+
+#ifndef MBED_TEXTDISPLAY_H
+#define MBED_TEXTDISPLAY_H
+
+#include "mbed.h"
+
+class TextDisplay : public Stream {
+public:
+
+    // functions needing implementation in derived implementation 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);
+    // putc (from Stream)
+    // printf (from Stream)
+    
+protected:
+
+    virtual int _putc(int value);
+    virtual int _getc();
+
+    // character location
+    short _column;
+    short _row;
+
+    // colours
+    int _foreground;
+    int _background;
+};
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextDisplays.h	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,20 @@
+/* mbed Text Displays Collection Library
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ *
+ * A library for providing a common base class for Text 
+ * displays, to provide commonality and simplify porting of new displays 
+ */
+
+#ifndef MBED_TEXT_DISPLAYS_H
+#define MBED_TEXT_DISPLAYS_H
+
+// Display Base Class
+#include "TextDisplay.h"
+
+// Text Displays
+#include "TextLCD.h"
+#include "Terminal.h"
+
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextLCD.cpp	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,98 @@
+/* mbed TextLCD Library
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+ 
+#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);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextLCD.h	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,30 @@
+/* mbed TextLCD Library Base Class
+ * Copyright (c) 2007-2009 sford
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+#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 class
+    
+protected:
+
+    void writeByte(int value);
+    void writeCommand(int command);
+    void writeData(int data);
+
+    DigitalOut _rw, _rs, _e;
+    BusOut _d;
+};
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,27 @@
+// simple test of the start of a generic Text Display arch, sford
+
+#include "mbed.h"
+
+#include "TextDisplays.h"
+
+TextLCD lcd1(p10, p11, p12, p15, p16, p29, p30); // rs, rw, e, d0-d3
+Terminal lcd2(USBTX, USBRX); // tx, rx
+
+int main() {
+    lcd1.printf("Hello World!\nHow are you?");
+    lcd2.printf("Hello World!\nHow are you?");
+
+    wait(2);
+
+    lcd1.locate(3,1);
+    lcd2.locate(3,1);
+    lcd1.foreground(0xFF0000);
+    lcd2.foreground(0xFF0000);
+    lcd1.printf("I'm Great!");
+    lcd2.printf("I'm Great!");
+
+    wait(3);
+
+    lcd1.cls();
+    lcd2.cls();
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed Nov 25 00:01:31 2009 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/32af5db564d4