Diff: LCD/LCD.cpp

Revision:

0:0c4fafa398b4

diff -r 000000000000 -r 0c4fafa398b4 LCD/LCD.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LCD/LCD.cpp	Wed Sep 26 12:15:00 2012 +0000
@@ -0,0 +1,143 @@
+/* mbed LCD Library, for a 4-bit LCD based on HD44780
+ * Copyright (c) 2007-2010, 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(0.00164);  // this command takes 1.64ms, so wait for it
+    }
+    writeByte(0x2);     // 4-bit mode
+    wait(0.0001f);    // 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(0.004100f);    // This command takes 4.1 ms
+    locate(0, 0);
+}
+
+void TextLCD::locate(int row, int column) {
+    _row = row;
+    _column = column;
+}
+
+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);  // most instructions take 100us
+    _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;
+    }
+}