Diff: main.cpp

Revision:

2:d87266912897

Parent:

1:1106d7adbe79

Child:

3:f18aa98bc9a8

--- a/main.cpp	Mon Nov 18 13:58:53 2013 +0000
+++ b/main.cpp	Wed Nov 20 11:07:09 2013 +0000
@@ -1,7 +1,21 @@
 // Hello World! for the TextLCD
+/*
+ * Heavily modified LCD "Hello world"
+ *
+ * LCD Library has been merged into program for convenience of development, and
+ * can be de-merged once its looking reliable
+ * currently this gives good results with a small LCD and with a LCD emulation VFD
+ * but is not reliable with a GU140x32-7806A graphic VFD
+ *
+ * Note E is set to 1 at end of cycle in an attempt to force a bug as display works fine
+ * on first power-up but tends to corrupt after MBED manual reset. I am speculating that
+ * something appears on MBED pins that the display "objects" to during a manual reset
+ *
+ */
 
 #include "mbed.h"
 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
+ * Copyright (c) 2013, oliverb, http://mbed.org
  * Copyright (c) 2007-2010, sford, http://mbed.org
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -32,18 +46,23 @@
  *
  * Currently supports 16x2, 20x2 and 20x4 panels
  *
+ * Implements a "Busy" flag to indicate when display is unavailable
+ * Busy is currently set by a timer and not by polling actual module
+ * 
+ * 
  * @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 {
+class TextLCD : public Stream
+{
 public:
 
     /** LCD panel format */
@@ -62,17 +81,9 @@
      * @param type  Sets the panel size/addressing mode (default = LCD16x2)
      */
     TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2);
-    
+
     void init();
-    void init2();
-    void init3();
-    void init4();
-    void init5();
-    void init6();
-    void init7();
-    void init8();
-    void init9();
-   
+
 
 #if DOXYGEN_ONLY
     /** Write a character to the LCD
@@ -86,7 +97,7 @@
      * @param format A printf-style format string, followed by the
      *               variables to use in formating the string.
      */
- volatile   int printf(const char* format, ...);
+    volatile   int printf(const char* format, ...);
 #endif
 
     /** Locate to a screen column and row
@@ -101,21 +112,34 @@
 
     int rows();
     int columns();
-    
+
     volatile int busy;
 
 protected:
     Timeout timer;
+
+// callbacks used by "init" to carry out steps of initialisation
+    void init2();
+    void init2b();
+
+    void init3();
+    void init4();
+    void init5();
+    void init6();
+    void init7();
+    void init8();
+//    void init9();
     // 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 character(int column, int row, int c);
     void writeByte(int value);
     void writeCommand(int command);
     void writeData(int data);
     void callback();
+    void locate_cb();
 
     DigitalOut _rs, _e;
     BusOut _d;
@@ -126,7 +150,7 @@
     char _queue[40];
     volatile int _head;
     volatile int _tail;
- //   int _loop;
+//   int _loop;
 };
 
 #endif
@@ -167,24 +191,37 @@
 
 TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
                  PinName d6, PinName d7, LCDType type) : busy(0),_rs(rs),
-        _e(e), _d(d4, d5, d6, d7),
-        _type(type) , _head(0), _tail(0) {}
+    _e(e), _d(d4, d5, d6, d7),
+    _type(type) , _column(0),_row(0),
+    _head(0), _tail(0) {}
 void TextLCD::init()
-{         
-        
+{
+
     busy=1;
+    _rs = 1;
+    _d  = 0;
+    wait_us(1);
     _e  = 0;
     _rs = 0;            // command mode
-    timer.attach(this,&TextLCD::init2,0.015);
+    timer.attach_us(this,&TextLCD::init2,15000);
 }
 void TextLCD::init2()
-{    
+{
+    _rs = 0;
+    _d = 0x3;
+    _e = 1;
+    wait_us(1);
+    _e = 0;
+    timer.attach_us(this,&TextLCD::init2b,4100);
+}
+void TextLCD::init2b()
+{
 
     _d = 0x3;
     _e = 1;
     wait_us(1);
     _e = 0;
-    timer.attach(this,&TextLCD::init3,0.0041);
+    timer.attach_us(this,&TextLCD::init3,4100);
 }
 void TextLCD::init3()
 {
@@ -192,7 +229,7 @@
     _e = 1;
     wait_us(1);
     _e = 0;
-    timer.attach(this,&TextLCD::init4,0.0001);
+    timer.attach_us(this,&TextLCD::init4,1000);
 }
 void TextLCD::init4()
 {
@@ -200,77 +237,117 @@
     _e = 1;
     wait_us(1);
     _e = 0;
-    timer.attach(this,&TextLCD::init5,0.000050);
+    timer.attach_us(this,&TextLCD::init5,60);
 }
 void TextLCD::init5()
 {
 
-    writeCommand(0x28); // Function set 001 BW N F - -
-    timer.attach(this,&TextLCD::init6,0.000050);
+    writeByte(0x28); // Function set 001 BW N F - -
+    timer.attach_us(this,&TextLCD::init6,60);
 }
 void TextLCD::init6()
 {
-    writeCommand(0x0C);
-    timer.attach(this,&TextLCD::init7,0.000050);
+    writeByte(0x0C);
+    timer.attach_us(this,&TextLCD::init7,60);
 }
 void TextLCD::init7()
 {
-    writeCommand(0x6);  // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
-    timer.attach(this,&TextLCD::init8,0.000050);
+    writeByte(0x6);  // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
+    timer.attach_us(this,&TextLCD::init8,60);
 }
 void TextLCD::init8()
 {
-    writeCommand(0x01); // cls, and set cursor to 0
-                       // This command takes 1.64 ms
-    timer.attach(this,&TextLCD::callback,0.00164);
+    writeByte(0x01); // cls, and set cursor to 0
+    // This command takes 1.64 ms
+    locate(0, 0);
+    timer.attach_us(this,&TextLCD::locate_cb,1640);
 }
-
-void TextLCD::character(int column, int row, int c) {
+/*
+void TextLCD::character(int column, int row, int c)
+{
     int a = address(column, row);
     writeCommand(a);
     writeData(c);
 }
-
-void TextLCD::cls() {
+*/
+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) {
+void TextLCD::locate(int column, int row)
+{
     _column = column;
     _row = row;
 }
+/* this is the general buffered-write callback for writing text to the display
+ * it normally chains to itself unless a newline occurs in which case it chains to
+ * locate_cb
+ * or the buffer runs out in which case it clears busy and does not chain
+ */
+
 void TextLCD::callback()
 {
-  if (_tail<_head)
-  {
-    _rs = 1; // data mode
-    writeByte(_queue[_tail++]);
-    timer.attach(this,&TextLCD::callback,0.000050f);
-  }
-  else
-  {
-    _head=_tail=0;
-    busy=0;
-  }
+    if (_tail<_head) {
+        int value=_queue[_tail++];
+        if (value == '\n') {
+            _column = 0;
+            _row++;
+            if (_row >= rows()) {
+                _row = 0;
+            }
+            locate_cb(); // newline isn't printed so go straight to "locate" code
+        } else {
+            _rs = 1; // data mode
+            writeByte(value);
+            _column++;
+            if (_column >= columns()) { //if we've reached the end of line then chain to "locate"
+                                        //otherwise go back to callback
+                _column = 0;
+                _row++;
+                if (_row >= rows()) {
+                    _row = 0;
+                }
+                timer.attach_us(this,&TextLCD::locate_cb,60);
+            } else {
+                timer.attach_us(this,&TextLCD::callback,60);
+            }
+
+        }
+
+    } else {  //if we've run out of text then clear flag
+        _head=_tail=0;
+        busy=0;
+    }
 }
 
-    
-    
+void TextLCD::locate_cb()
+{
+    int a = address(_column, _row);
+    _rs=0;
+    writeByte(a);
+    timer.attach_us(this,&TextLCD::callback,60);
+}
 
-int TextLCD::_putc(int value) 
+
+int TextLCD::_putc(int value)
 {
-  if (_head<40)
-  {
-    _queue[_head++]=value;
-  };
-  if (!busy)
-  {
-    busy=1;
-    callback();
-  };
-  return value;
+    if (_head<40) {
+        _queue[_head++]=value;
+    };
+    if (busy==0) {
+        busy=1;
+        locate_cb(); // set cursor position before text
+        /*
+        int a = address(_column, _row);
+        _rs=0;
+        writeByte(a);
+        timer.attach_us(this,&TextLCD::callback,60);
+        */
+    };
+    return value;
 }
 
 /*{
@@ -294,35 +371,40 @@
     return value;
 }
 */
-int TextLCD::_getc() {
+int TextLCD::_getc()
+{
     return -1;
 }
 
-void TextLCD::writeByte(int value) {
+void TextLCD::writeByte(int value)
+{
     _d = value >> 4;
     _e = 1;
     wait_us(1);
     _e = 0;
     _d = value >> 0;
-    wait_us(1);
+    wait_us(2);
     _e = 1;
     wait_us(1);  // most instructions take 40us
     _e = 0;
 }
 
-void TextLCD::writeCommand(int command) {
+void TextLCD::writeCommand(int command)
+{
     _rs = 0;  //command mode
     wait_us(50); // most instructions take 40us
     writeByte(command);
 }
 
-void TextLCD::writeData(int data) {
+void TextLCD::writeData(int data)
+{
     _rs = 1; // data mode
     wait_us(50); // most instructions take 40us
     writeByte(data);
 }
 
-int TextLCD::address(int column, int row) {
+int TextLCD::address(int column, int row)
+{
     switch (_type) {
         case LCD20x4:
             switch (row) {
@@ -344,7 +426,8 @@
     }
 }
 
-int TextLCD::columns() {
+int TextLCD::columns()
+{
     switch (_type) {
         case LCD20x4:
         case LCD20x2:
@@ -356,7 +439,8 @@
     }
 }
 
-int TextLCD::rows() {
+int TextLCD::rows()
+{
     switch (_type) {
         case LCD20x4:
             return 4;
@@ -368,20 +452,26 @@
     }
 }
 
-TextLCD lcd(p15, p16, p17, p18, p19, p20); // rs, e, d4-d7
+TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); // rs, e, d4-d7
 
 
-int main() {
-    Led1=1;
-    lcd.init();
-    Led2=1;
-    Led1=0;
-  //  while (lcd.busy) {}
-    Led3=1;
-    Led2=0;
-    lcd.printf("Hello World!\n");
-    Led4=1;
-    Led3=0;
-    while (lcd.busy) {}
-    Led1=1;
+int main()
+{
+    while(1) {
+        Led1=1;
+        lcd.init();
+        Led2=1;
+        Led1=0;
+        while (lcd.busy) {}
+        Led3=1;
+        Led2=0;
+        lcd.printf("Test String that goes over end of line!\n");
+        Led4=1;
+        Led3=0;
+        while (lcd.busy) {}
+        Led1=1;
+        wait(1);
+        // DigitalOut E(p17);
+        // E=1; // try to break it
+    }
 }