Diff: TextLCD_SR4.cpp

Revision:

0:580f94424a91

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TextLCD_SR4.cpp	Mon Oct 25 22:40:36 2010 +0000
@@ -0,0 +1,179 @@
+/* mbed TextLCD_SR4 Library, for a 4-bit LCD based on HD44780
+ * Copyright (c) 2007-2010, sford
+ *
+ * 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.
+ */
+
+/*
+ * Modified for http://mbed.org/users/shintamainjp/notebook/textlcd_sr4_en/
+ * Shinichiro Nakamura
+ */
+
+#include "TextLCD_SR4.h"
+#include "mbed.h"
+
+TextLCD_SR4::TextLCD_SR4(PinName rs, PinName e, PinName dat, PinName clk, LCDType type)
+        : _rs(rs), _e(e), _dat(dat), _clk(clk), _type(type) {
+
+    _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_SR4::character(int column, int row, int c) {
+    int a = address(column, row);
+    writeCommand(a);
+    writeData(c);
+}
+
+void TextLCD_SR4::cls() {
+    writeCommand(0x01); // cls, and set cursor to 0
+    wait(0.00164f);     // This command takes 1.64 ms
+    locate(0, 0);
+}
+
+void TextLCD_SR4::locate(int column, int row) {
+    _column = column;
+    _row = row;
+}
+
+int TextLCD_SR4::_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_SR4::_getc() {
+    return -1;
+}
+
+void TextLCD_SR4::writeByte(int value) {
+    writeToShiftRegister(value << 0);
+    wait(0.000040f); // most instructions take 40us
+    _e = 0;
+    wait(0.000040f);
+    _e = 1;
+    writeToShiftRegister(value << 4);
+    wait(0.000040f);
+    _e = 0;
+    wait(0.000040f);  // most instructions take 40us
+    _e = 1;
+}
+
+void TextLCD_SR4::writeToShiftRegister(int value) {
+    /*
+     * MSB first.
+     */
+    for (int i = 0; i < 8; i++) {
+        if (value & (1 << (7 - i))) {
+            _dat = 1;
+        } else {
+            _dat = 0;
+        }
+        _clk = 1;
+        wait_us(1);
+        _clk = 0;
+        wait_us(1);
+    }
+}
+
+void TextLCD_SR4::writeCommand(int command) {
+    _rs = 0;
+    writeByte(command);
+}
+
+void TextLCD_SR4::writeData(int data) {
+    _rs = 1;
+    writeByte(data);
+}
+
+int TextLCD_SR4::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_SR4::columns() {
+    switch (_type) {
+        case LCD20x4:
+        case LCD20x2:
+            return 20;
+        case LCD16x2:
+        case LCD16x2B:
+        default:
+            return 16;
+    }
+}
+
+int TextLCD_SR4::rows() {
+    switch (_type) {
+        case LCD20x4:
+            return 4;
+        case LCD16x2:
+        case LCD16x2B:
+        case LCD20x2:
+        default:
+            return 2;
+    }
+}