Diff: LCD/LCD.cpp

Revision:

0:3087f1924901

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LCD/LCD.cpp	Wed Dec 09 20:58:55 2015 +0000
@@ -0,0 +1,186 @@
+/* mbed LCD Library, for a 4-bit LCD based on HD44780
+ * Copyright (c) 2007-2012, hb9gaa
+ */
+
+#include "LCD.h"
+#include "mbed.h"
+
+TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, LCDType type) : _rs(rs), _rw(rw), _e(e), _d(d0, d1, d2, d3), _type(type) 
+    {
+    _e  = 1;
+    _rw = 0;
+    _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_ms(1.64);      // this command takes 1.64ms, so wait for it
+        }
+    writeByte(0x2);         // 4-bit mode
+    wait_ms(0.1);           // most instructions take 100us
+
+    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_ms(4.1);           // This command takes 4.1 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(0.0001);       // most instructions take 100us
+    _e = 0;
+    wait(0.0001);
+    _e = 1;
+    _d = value >> 0;
+    wait(0.0001);
+    _e = 0;
+    wait(0.0001);
+    _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 * 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;
+        }
+    }
+
+
+void TextLCD::buildChar(unsigned char *p)
+    {
+     unsigned char i, j;
+     
+     for(j=0;j<8;j++)                    //CGRAM Adresse
+         {
+         writeCommand(0x40+(j*8));       //Write to CGRAM
+         for(i=0;i<8;i++)
+            writeData(p[i+(j*8)]);       //Write the character pattern to CGRAM
+         }
+        writeCommand(0x80);              //shift back to DDRAM location 0
+    }