Diff: TextLCD.cpp

Revision:

2:2773889d6143

Parent:

0:5dc369cc8778

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextLCD.cpp	Sat Feb 05 23:20:53 2011 +0000
@@ -0,0 +1,172 @@
+/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
+ * Copyright (c) 2007-2010, sford, http://mbed.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * 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
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "ext_text_lcd/TextLCD.h"
+#include "mbed.h"
+
+namespace ext_text_lcd {
+
+namespace {
+    int makeLcdAddress(const TextLCD::LCDType &type, int column, int row) {
+        return column + row * 0x40;
+    }
+    
+    int makeLcdAddress40(const TextLCD::LCDType &type, int column, int row) {
+        return column + row * 40;
+    }
+    
+    int makeLcdAddress4Rows(const TextLCD::LCDType &type, int column, int row) {
+        return column + (row % 2) * 0x40 + (row / 2) * 20;
+    }
+}
+
+const TextLCD::LCDType TextLCD::LCD16x2(16, 2, makeLcdAddress);
+const TextLCD::LCDType TextLCD::LCD16x2B(16, 2, makeLcdAddress40);
+const TextLCD::LCDType TextLCD::LCD20x2(20, 2, makeLcdAddress);
+const TextLCD::LCDType TextLCD::LCD20x4(20, 4, makeLcdAddress4Rows);
+
+TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
+                 PinName d6, PinName d7, const LCDType &type) : 
+    _rs(rs), _e(e), _output(new BusOutput(d4, d5, d6, d7)),
+    _type(type)
+{
+    init();
+}
+
+TextLCD::TextLCD(PinName rs, PinName e, PortName dport, std::size_t dlsb, 
+                 const LCDType &type) :
+    _rs(rs), _e(e), _output(new PortOutput(dport, dlsb)),
+    _type(type)
+{
+    init();
+}
+
+void TextLCD::init() {
+    _e  = 1;
+    _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(0.000040f);    // most instructions take 40us
+
+    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::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) {
+    _column = column;
+    _row = row;
+    
+    int a = address(column, row);
+    writeCommand(0x80 | a);
+}
+
+int TextLCD::_putc(int value) {
+    int column = _column;
+    int row = _row;
+    if (value == '\n') {
+        column = 0;
+        row = _row+1;
+    } else {
+        writeData(value);
+        column++;
+        if (column < columns()) {
+            return value;
+        }
+        
+        column = 0;
+        row++;
+    }
+    if (row >= rows()) {
+        row = 0;
+    }
+    locate(column, row);
+    return value;
+}
+
+int TextLCD::_getc() {
+    return -1;
+}
+
+void TextLCD::writeByte(int value) {
+    _output->writeNibble(value >> 4);
+    wait(0.000040f); // most instructions take 40us
+    _e = 0;
+    wait(0.000040f);
+    _e = 1;
+    _output->writeNibble(value);
+    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);
+}
+
+void TextLCD::setDisplayControl(DisplayControl d, CursorDisplayControl c, CursorStyle b)
+{
+    writeCommand(0x08 | d | c | b);
+}
+
+void TextLCD::writeToCGMem(unsigned addr, const char *buffer, std::size_t size)
+{
+    writeCommand(0x40 | (addr & 0x3f));
+    while (size > 0) {
+        writeData(*buffer);
+        size--;
+        buffer++;
+    }
+    
+    locate(_column, _row);
+}
+
+void TextLCD::BusOutput::writeNibble(int value) {
+    _bus = value; 
+}
+
+void TextLCD::PortOutput::writeNibble(int value) {
+    _port = value << _shift;
+}
+
+} // ext_text_lcd namespace