Diff: user_interface/TextLCD23017.cpp

Revision:

0:371773dd3dd1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/user_interface/TextLCD23017.cpp	Wed May 04 15:41:13 2011 +0000
@@ -0,0 +1,235 @@
+/* mbed TextLCD23017 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 <stdarg.h>
+#include "TextLCD23017.h"
+#include "mbed.h"
+
+/**************************************************************
+Port A: databus 8-bit bidir, also used as input for keys (A2-A7)
+IntA wired to mbed pin??
+PortB: B0 out: keys out, set low to read keys on PortA
+       B1 in:  rot.enc. push button act.L
+       B2 out: buzzer
+       B3 in:  rot.enc. A
+       B4 in:  rot.enc. B
+       B5 out: LCD E (CS\)
+       B6 out: LCD R\W (WR\)
+       B7 out: LCD RS (A0)
+**************************************************************/
+TextLCD23017::TextLCD23017(MCP23017& intf, LCDType type) : _intf(intf), _type(type) {
+    ::printf("creating lcd\n");
+    wait(0.015);        // Wait 15ms to ensure powered up of LCD
+//init the MCP23017
+    intf.direction(PORT_A, PORT_DIR_IN); //input
+    intf.direction(PORT_B, INPUTS);// rot enc input
+    intf.configurePullUps(PORT_A, PORT_DIR_IN);
+    intf.configurePullUps(PORT_B, INPUTS);
+    intf.write(PORT_B, 0x00); //enable keys
+    //intf.interruptPolarity(ACTIVE_LOW);
+    intf.mirrorInterrupts(true);
+    
+//initialisation according to HD44780 datasheet
+    // send "Display Settings" 2 times for 8 bit interface
+    writeByte(0x30);
+    wait(0.0041);  // this command takes 4.1ms, so wait for it
+    writeByte(0x30);
+
+
+    writeByte(0x38);     // 8-bit mode, 2 lines 8x5 font
+    //wait(0.000040f);    // most instructions take 40us
+    writeByte(0x08);  //display off, cursor off
+    writeByte(0x01);  //clear display
+    writeByte(0x06);  //increment, no shift
+//from here on busy can be tested
+
+    writeCommand(0x0F); //display on, cursor on, blink on
+//    cls();
+::printf("lcd created\n");
+}
+
+int TextLCD23017::printf (char * format, ...) {
+    char buffer[40];
+    va_list args;
+    va_start (args, format);
+    int rv=vsprintf (buffer,format, args);
+//    ::printf("printing:'%s'\n", buffer);
+    writeString (buffer);
+    va_end (args);
+    return rv;
+}
+
+//busy not used, i2c is slow enough
+bool TextLCD23017::busy() {//assume PORT_A is input, PORT_A intr disabled, takes minimum 10bytes ~1ms
+//setup and hold of RS-E are not met!
+    _intf.write(PORT_B, RW|E|KEYS); //read R=1, E=1, disable keys
+    _ar = _intf.read(PORT_A);
+    _intf.write(PORT_B, KEYS); //read R=0, E=0
+    return (_ar & 0x80) ;//return with keys disabled
+}
+
+void TextLCD23017::character(int column, int row, int c) {
+    int a = address(column, row);
+    writeCommand(a);
+    writeData(c);
+}
+
+void TextLCD23017::cls() {
+    writeCommand(0x01); // cls, and set cursor to 0
+    wait(0.00164f);     // This command takes 1.64 ms
+    locate(0, 0);
+}
+
+void TextLCD23017::locate(int column, int row) {
+    _column = column;
+    _row = row;
+}
+
+int TextLCD23017::_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 TextLCD23017::_getc() {
+    return -1;
+}
+
+void TextLCD23017::writeByte(int value) {//5 transactions of 3 bytes ~150bits ~1.5ms
+    _intf.direction(PORT_A, PORT_DIR_OUT); //set to output
+    _intf.write(PORT_A, value);//put value on data bus
+    _intf.write(PORT_B, E|KEYS);//write instruction register, E=1
+    _intf.write(PORT_B, KEYS);//E returns to 0
+    _intf.direction(PORT_A, PORT_DIR_IN); //set to input
+}
+
+void TextLCD23017::writeCommand(int command) {//3 transactions 3 bytes ~0.9ms + busy + writeByte = 3.4ms
+//    while (busy()) /*wait*/ ;
+    writeByte(command);
+    _intf.write(PORT_B, 0);//enable keys
+}
+
+void TextLCD23017::writeData(int data) {
+//    while (busy()) /*wait*/ ;
+    _intf.direction(PORT_A, PORT_DIR_OUT); //set to output
+    _intf.write(PORT_A, data);//put data on data bus
+    _intf.write(PORT_B, RS|KEYS);//setup RS
+    _intf.write(PORT_B, E|RS|KEYS);//write data register, E=1, RS=1
+    _intf.write(PORT_B, RS|KEYS);//E returns to 0
+    _intf.direction(PORT_A, PORT_DIR_IN); //set to input
+    _intf.write(PORT_B, 0);//enable keys
+}
+
+void TextLCD23017::writeString(char *s) {//convert a string into LCD commands
+    char buffer[240];//size must be > 4*strlen(s) + 7
+    char *p = strtok(s,"\n");
+    _intf.direction(PORT_A, PORT_DIR_OUT); //set to output
+    //assume RS=0, E=0, R/W = 0
+    while (p) {
+//    ::printf("section:'%s'\n", p);
+        int i = 0;
+        if (p != s) {//don't do this the first time (not a newline)
+            _column = 0;
+            if (++_row >= rows()) _row = 0;
+        }
+        buffer[i++] = E|KEYS;//B, clock RS and RW
+        buffer[i++] = address(_column, _row);//A, this data is used
+        buffer[i++] = KEYS;//B, clock data
+        buffer[i++] = address(_column, _row);//A, dummy
+        buffer[i++] = RS|KEYS;//B, setup RS
+        for (int j = 0; j < strlen(p) && i<sizeof(buffer)-4; j++) {
+            buffer[i++] = p[j];//A, dummy
+            buffer[i++] = E|RS|KEYS;//B, clock RS and RW
+            buffer[i++] = p[j];//A, this data is used
+            buffer[i++] = RS|KEYS;//B, clock data
+            if (++_column >= columns()) {
+                _column = 0;
+                if (++_row >= rows())  _row = 0;
+            }
+        }//RS=1, E=0, RW=0
+        p = strtok(0, "\n");
+        buffer[i++] = 0;//A, dummy
+        buffer[i++] = (p!=0) ? KEYS : 0; //B, release RS
+        _intf.write(PORT_B, buffer, i, p != 0);//start with B, send all substrings as a single transaction
+    }
+    _intf.direction(PORT_A, PORT_DIR_IN); //set to input
+}
+
+int TextLCD23017::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 TextLCD23017::columns() {
+    switch (_type) {
+        case LCD20x4:
+        case LCD20x2:
+            return 20;
+        case LCD16x2:
+        case LCD16x2B:
+        default:
+            return 16;
+    }
+}
+
+int TextLCD23017::rows() {
+    switch (_type) {
+        case LCD20x4:
+            return 4;
+        case LCD16x2:
+        case LCD16x2B:
+        case LCD20x2:
+        default:
+            return 2;
+    }
+}