Diff: menbed/displays/menbedDisplayHD44780.cpp

Revision:

3:ec80bb6ff5da

Parent:

0:936f1c020120

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/menbed/displays/menbedDisplayHD44780.cpp	Tue Sep 11 10:21:10 2012 +0000
@@ -0,0 +1,369 @@
+/* This code based on 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 "mbed.h"
+#include "include/menbedDisplayHD44780.h"
+#include "menbedDisplay.h"
+
+MenbedDisplayHD44780::MenbedDisplayHD44780 (PinName rs, PinName e, 
+    PinName d4, PinName d5, PinName d6, PinName d7, LCDSize size) : 
+    rs(rs), e(e), d(d4, d5, d6, d7), size(size) 
+{
+    this->e  = 1;
+    this->rs = 0;
+    
+    upArrowVisible = false;
+    downArrowVisible = false;
+    topLineSelected = false;
+    bottomLineSelected = false;
+    cursorCol = -1;
+    cursorRow = -1;
+
+    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); // Display on but keep cursor and blinking off
+    writeCommand(0x6);  // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
+    
+    loadCustomChars();
+    
+    clear();
+}
+
+
+bool MenbedDisplayHD44780::writeLine (const char *line, uint8_t row)
+{
+    int i = 0;
+    int cursorPos = -1;
+
+    if (row >= rows())
+        return false;
+
+    // Skip writing to the left-most column to leave space for the selector
+    // and up/down arrows that will be filled in later.
+    gotoPosition (row, 1);
+
+    while ((line[i] != '\0') && (line[i] != '\n') && (i+1 < columns()))
+    {
+        // Place the cursor at the end of the active parameter, when it exists.
+        // A parameter is active when it is highlighted as indicated by the 
+        // MSB of the character code being set.
+        if ((i > 0) && (line[i-1] & 0x80) && !(line[i] & 0x80))
+            cursorPos = i-1;
+
+        // Print each character to the display after clearing its MSB so that
+        // it prints as a standard ASCII character.
+        writeData (line[i] & ~0x80);
+        i++;
+    }
+    
+    // If the first character of the line is not highlighted but the last is,
+    // a parameter must be selected for editing, and we place the cursor at
+    // the end of the parameter which, in this special case, corresponds to
+    // the end of the line.
+    if (!(line[0] & 0x80) && (line[i-1] & 0x80))
+        cursorPos = i-1;
+
+    // Fill the remainder of the row with spaces to overwrite any old data
+    while (i++ < columns() - 1)
+        writeData(' ');
+
+    // Now go back and fill in the selector and up/down arrows
+    gotoPosition(row, 0);
+    if ((line[0] & 0x80) && (cursorPos == -1))
+    {
+        if (row == 0)
+            topLineSelected = true;
+        else if (row == rows() - 1)
+            bottomLineSelected = true;
+    
+        if ((row == 0) && upArrowVisible)
+            writeData (CharUP_SELECT);
+        else if ((row == rows() - 1) && downArrowVisible)
+            writeData (CharDOWN_SELECT);
+        else
+            writeData (CharSELECT);
+    }
+    else
+    {
+        if (row == 0)
+            topLineSelected = false;
+        else if (row == rows() - 1)
+            bottomLineSelected = false;
+    
+        if ((row == 0) && upArrowVisible)
+            writeData (CharUP);
+        else if ((row == rows() - 1) && downArrowVisible)
+            writeData (CharDOWN);
+        else
+            writeData (' ');
+    }
+
+    // If a parameter is being edited, we turn on the blinking cursor.
+    if (cursorPos != -1)
+    {
+        cursorRow = row;
+        cursorCol = cursorPos + 1;
+        gotoPosition (cursorRow, cursorCol); // Add 1 to account for selector col.
+        cursorOn();
+    }
+    // If this line used to contain the cursor but should not any more reset
+    // the cursor row and column position and turn it off.
+    else if (row == cursorRow)
+    {
+        cursorRow = -1;
+        cursorCol = -1;
+        cursorOff();
+    }
+
+    return true;
+}
+
+
+void MenbedDisplayHD44780::showUpArrow (bool show)
+{
+    upArrowVisible = show;
+    
+    gotoPosition (0, 0);
+    
+    if (show && topLineSelected)
+        writeData (CharUP_SELECT);
+    else if (!show && topLineSelected)
+        writeData (CharSELECT);
+    else if (show && !topLineSelected)
+        writeData (CharUP);
+    else
+        writeData(' ');
+        
+    // Return cursor to its original location
+    if ((cursorRow >= 0) && (cursorCol >= 0))
+        gotoPosition (cursorRow, cursorCol);
+}
+
+
+void MenbedDisplayHD44780::showDownArrow (bool show)
+{
+    downArrowVisible = show;
+    
+    gotoPosition (rows() - 1, 0);
+    
+    if (show && bottomLineSelected)
+        writeData (CharDOWN_SELECT);
+    else if (!show && bottomLineSelected)
+        writeData (CharSELECT);
+    else if (show && !bottomLineSelected)
+        writeData (CharDOWN);
+    else
+        writeData(' ');
+        
+    // Return cursor to its original location
+    if ((cursorRow >= 0) && (cursorCol >= 0))
+        gotoPosition (cursorRow, cursorCol);
+}
+
+
+uint8_t MenbedDisplayHD44780::getLines (void)
+{
+    return rows();
+}
+
+
+uint8_t MenbedDisplayHD44780::getLineLength (void)
+{
+    return columns();
+}
+
+
+void MenbedDisplayHD44780::clear()
+{
+    writeCommand (0x01); // Clear, and set cursor to 0
+    wait (0.050f);
+    gotoPosition (0, 0);
+}
+
+
+bool MenbedDisplayHD44780::gotoPosition(int row, int column)
+{
+    if ((column < 0) || (column >= columns()) || (row < 0) || (row >= rows()))
+        return false;
+
+    writeCommand (address (row, column));
+    return true;
+}
+
+
+void MenbedDisplayHD44780::cursorOn()
+{
+    writeCommand(0x0D); // Display and blinking on, cursor off
+}
+
+
+void MenbedDisplayHD44780::cursorOff()
+{
+    writeCommand(0x0C); // Display on, cursor and blinking off
+}
+
+
+void MenbedDisplayHD44780::writeCommand(int command) {
+    rs = 0;
+    writeByte(command);
+}
+
+
+void MenbedDisplayHD44780::writeData(int data) {
+    rs = 1;
+    writeByte(data);
+}
+
+
+void MenbedDisplayHD44780::writeByte(int value) {
+    d = value >> 4;
+    wait(0.000040f); // most instructions take 40us
+    e = 0;
+    wait(0.000040f);
+    e = 1;
+    d = value >> 0;
+    wait(0.000040f);
+    e = 0;
+    wait(0.000040f);  // most instructions take 40us
+    e = 1;
+}
+
+
+int MenbedDisplayHD44780::address(int row, int column) {
+    switch (size) {
+        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 MenbedDisplayHD44780::columns() 
+{
+    switch (size) {
+        case LCD20x4:
+        case LCD20x2:
+            return 20;
+        case LCD16x2:
+        case LCD16x2B:
+        default:
+            return 16;
+    }
+}
+
+
+int MenbedDisplayHD44780::rows() 
+{
+    switch (size) {
+        case LCD20x4:
+            return 4;
+        case LCD16x2:
+        case LCD16x2B:
+        case LCD20x2:
+        default:
+            return 2;
+    }
+}
+
+
+void MenbedDisplayHD44780::loadCustomChars (void)
+{
+
+    // Up arrow
+    writeCommand(0x40 + (8 * CharUP));
+    writeData(0x04);
+    writeData(0x0E);
+    writeData(0x1F);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    
+    // Up arrow with selector
+    writeCommand(0x40 + (8 * CharUP_SELECT));
+    writeData(0x04);
+    writeData(0x0E);
+    writeData(0x1F);
+    writeData(0x00);
+    writeData(0x1F);
+    writeData(0x1F);
+    writeData(0x00);
+    writeData(0x00);
+    
+    // Selector alone
+    writeCommand(0x40 + (8 * CharSELECT));
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x1F);
+    writeData(0x1F);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);    
+    
+    // Down arrow with selector
+    writeCommand(0x40 + (8 * CharDOWN_SELECT));
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x1F);
+    writeData(0x1F);
+    writeData(0x00);
+    writeData(0x1F);
+    writeData(0x0E);
+    writeData(0x04);
+    
+    // Down arrow
+    writeCommand(0x40 + (8 * CharDOWN));
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x00);
+    writeData(0x1F);
+    writeData(0x0E);
+    writeData(0x04);        
+}
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