Aleksei Gimbitskii
made some changes in config header file to make this library work with 1602A display and PCF8574AT I2C-bus interface
Fork of
TextLCD
by 
Wim Huiskamp
Revision 8:03116f75b66e, committed 2013-01-29
- Comitter:
- wim
- Date:
- Tue Jan 29 20:49:33 2013 +0000
- Parent:
- 7:44f34c09bd37
- Child:
- 9:0893d986e717
- Commit message:
- TextLCD Update to fix memoryaddress problems
Changed in this revision
| TextLCD.cpp | Show annotated file Show diff for this revision Revisions of this file |
| TextLCD.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/TextLCD.cpp Sat Dec 04 11:29:57 2010 +0000
+++ b/TextLCD.cpp Tue Jan 29 20:49:33 2013 +0000
@@ -1,5 +1,6 @@
/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
* Copyright (c) 2007-2010, sford, http://mbed.org
+ * 2013, WH, Updated LCD types and fixed lcd address issues
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@@ -43,16 +44,19 @@
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
+ writeCommand(0x06); // 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);
+ int addr = getAddress(column, row);
+
+ writeCommand(0x80 | addr);
writeData(c);
}
+
void TextLCD::cls() {
writeCommand(0x01); // cls, and set cursor to 0
wait(0.00164f); // This command takes 1.64 ms
@@ -112,6 +116,12 @@
writeByte(data);
}
+
+#if (0)
+// This is the original method.
+// It is confusing since it returns the memoryaddress or-ed with the set memorycommand 0x80.
+// Left it in here for compatibility with older code. New applications should use getAddress() instead.
+//
int TextLCD::address(int column, int row) {
switch (_type) {
case LCD20x4:
@@ -133,27 +143,116 @@
return 0x80 + (row * 0x40) + column;
}
}
+#endif
+
+
+// This replaces the original method.
+// Left it in here for compatibility with older code. New applications should use getAddress() instead.
+int TextLCD::address(int column, int row) {
+ return 0x80 | getAddress(column, row);
+}
+
+// This is new method to return the memory address based on row, column and displaytype.
+//
+int TextLCD::getAddress(int column, int row) {
+
+ switch (_type) {
+ case LCD8x1:
+ return 0x00 + column;
+
+ case LCD16x4:
+ switch (row) {
+ case 0:
+ return 0x00 + column;
+ case 1:
+ return 0x40 + column;
+ case 2:
+ return 0x10 + column;
+ case 3:
+ return 0x50 + column;
+ }
+
+ case LCD20x4:
+ switch (row) {
+ case 0:
+ return 0x00 + column;
+ case 1:
+ return 0x40 + column;
+ case 2:
+ return 0x14 + column;
+ case 3:
+ return 0x54 + column;
+ }
+
+// Not sure about this one, seems wrong.
+ case LCD16x2B:
+ return 0x00 + (row * 40) + column;
+
+ case LCD8x2:
+ case LCD16x2:
+ case LCD20x2:
+ case LCD24x2:
+ return 0x00 + (row * 0x40) + column;
+
+// Should never get here.
+ default:
+ return 0x00;
+ }
+}
+
+
+// Added for consistency. Set row, colum and update memoryaddress.
+//
+void TextLCD::setAddress(int column, int row) {
+
+ locate(column, row);
+
+ int addr = getAddress(column, row);
+
+ writeCommand(0x80 | addr);
+}
int TextLCD::columns() {
switch (_type) {
- case LCD20x4:
- case LCD20x2:
- return 20;
+ case LCD8x1:
+ case LCD8x2:
+ return 8;
+
case LCD16x2:
case LCD16x2B:
+ case LCD16x4:
+ return 16;
+
+ case LCD20x2:
+ case LCD20x4:
+ return 20;
+
+ case LCD24x2:
+ return 24;
+
+// Should never get here.
default:
- return 16;
+ return 0;
}
}
int TextLCD::rows() {
switch (_type) {
- case LCD20x4:
- return 4;
+ case LCD8x1:
+ return 1;
+
+ case LCD8x2:
case LCD16x2:
case LCD16x2B:
case LCD20x2:
+ case LCD24x2:
+ return 2;
+
+ case LCD16x4:
+ case LCD20x4:
+ return 4;
+
default:
- return 2;
+ return 0;
}
}
--- a/TextLCD.h Sat Dec 04 11:29:57 2010 +0000
+++ b/TextLCD.h Tue Jan 29 20:49:33 2013 +0000
@@ -1,5 +1,6 @@
/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
* Copyright (c) 2007-2010, sford, http://mbed.org
+ * 2013, WH, Updated LCD types and fixed lcd address issues
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@@ -27,7 +28,7 @@
/** A TextLCD interface for driving 4-bit HD44780-based LCDs
*
- * Currently supports 16x2, 20x2 and 20x4 panels
+ * Currently supports 8x1, 8x2, 16x2, 16x4, 20x2, 20x4 and 24x2 panels
*
* @code
* #include "mbed.h"
@@ -40,15 +41,20 @@
* }
* @endcode
*/
+
class TextLCD : public Stream {
public:
/** LCD panel format */
enum LCDType {
- LCD16x2 /**< 16x2 LCD panel (default) */
- , LCD16x2B /**< 16x2 LCD panel alternate addressing */
- , LCD20x2 /**< 20x2 LCD panel */
- , LCD20x4 /**< 20x4 LCD panel */
+ LCD8x1, /**< 8x1 LCD panel */
+ LCD8x2, /**< 8x2 LCD panel */
+ LCD16x2, /**< 16x2 LCD panel (default) */
+ LCD16x2B, /**< 16x2 LCD panel alternate addressing */
+ LCD16x4, /**< 16x4 LCD panel */
+ LCD20x2, /**< 20x2 LCD panel */
+ LCD20x4, /**< 20x4 LCD panel */
+ LCD24x2 /**< 24x2 LCD panel */
};
/** Create a TextLCD interface
@@ -94,7 +100,9 @@
virtual int _putc(int value);
virtual int _getc();
- int address(int column, int row);
+ int address(int column, int row);
+ int getAddress(int column, int row);
+ void setAddress(int column, int row);
void character(int column, int row, int c);
void writeByte(int value);
void writeCommand(int command);