Revision 2:227356c7d12c, committed 2010-05-27

Comitter:

simon

Date:

Thu May 27 17:52:15 2010 +0000

Parent:

1:ac48b187213c

Child:

3:2a46d5820a78

Commit message:

Changed in this revision

--- a/TextLCD.cpp	Thu May 27 13:44:15 2010 +0000
+++ b/TextLCD.cpp	Thu May 27 17:52:15 2010 +0000
@@ -23,33 +23,6 @@
 #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),

--- a/TextLCD.h	Thu May 27 13:44:15 2010 +0000
+++ b/TextLCD.h	Thu May 27 17:52:15 2010 +0000
@@ -7,10 +7,10 @@
  * 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
@@ -24,48 +24,90 @@
 #define MBED_TEXTLCD_H
 
 #include "mbed.h"
+
+/** A TextLCD interface for 4-bit HD44780-based LCDs
+ *
+ * Supports a number of different panel configurations
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "TextLCD.h"
+ *
+ * TextLCD lcd(p5, p6, p7, p8, p9);
+ *
+ * int main() {
+ *     lcd.printf("Hello World!\n");
+ * }
+ * @endcode
+ */
 class TextLCD : public Stream {
 public:
 
-    // the different LCDs and addressing modes
-    /** Select the type of LCD */
+    /** LCD panel format */
     enum LCDType {
-        LCD16x2
-        , LCD16x2B
-        , LCD20x2
-        , LCD20x4
+        LCD16x2     /**< 16x2 LCD panel (default) */
+        , LCD16x2B  /**< 16x2 LCD panel alternate addressing */
+        , LCD20x2   /**< 20x2 LCD panel */
+        , LCD20x4   /**< 20x4 LCD panel */
     };
 
+    /** Create a TextLCD interface
+     *
+     * @param rs    Instruction/data control line
+     * @param e     Enable line (clock)
+     * @param d0-d3 Data lines
+     * @param type  Sets the panel size/addressing mode (default = LCD16x2)
+     */
     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);
+
+#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();  
-    
-    
+    int columns();
+
 protected:
 
     // Stream implementation functions
     virtual int _putc(int value);
     virtual int _getc();
 
-    // internal tx functions
+    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);
-    int address(int column, int row);
 
     DigitalOut _rs, _e;
     BusOut _d;
     LCDType _type;
 
-    // current row/column
     int _column;
     int _row;
 };
 
+}
+
 #endif

--- a/main.cpp	Thu May 27 13:44:15 2010 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,43 +0,0 @@
-// 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);
-    }
-}

--- a/mbed.bld	Thu May 27 13:44:15 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/e6be4cd80aad