Wim Huiskamp
Updated for more display types. Fixed memoryaddress confusion in address() method. Added new getAddress() method. Added support for UDCs, Backlight control and other features such as control through I2C and SPI port expanders and controllers with native I2C and SPI interfaces. Refactored to fix issue with pins that are default declared as NC.
Dependents: GPSDevice TestTextLCD SD to Flash Data Transfer DrumMachine ... more
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TextLCD
by 
Simon Ford
Example
Hello World! for the TextLCD
#include "mbed.h"
#include "TextLCD.h"
// Host PC Communication channels
Serial pc(USBTX, USBRX); // tx, rx
// I2C Communication
I2C i2c_lcd(p28,p27); // SDA, SCL
// SPI Communication
SPI spi_lcd(p5, NC, p7); // MOSI, MISO, SCLK
//TextLCD lcd(p15, p16, p17, p18, p19, p20); // RS, E, D4-D7, LCDType=LCD16x2, BL=NC, E2=NC, LCDTCtrl=HD44780
//TextLCD_SPI lcd(&spi_lcd, p8, TextLCD::LCD40x4); // SPI bus, 74595 expander, CS pin, LCD Type
TextLCD_I2C lcd(&i2c_lcd, 0x42, TextLCD::LCD20x4); // I2C bus, PCF8574 Slaveaddress, LCD Type
//TextLCD_I2C lcd(&i2c_lcd, 0x42, TextLCD::LCD16x2, TextLCD::WS0010); // I2C bus, PCF8574 Slaveaddress, LCD Type, Device Type
//TextLCD_SPI_N lcd(&spi_lcd, p8, p9); // SPI bus, CS pin, RS pin, LCDType=LCD16x2, BL=NC, LCDTCtrl=ST7032_3V3
//TextLCD_I2C_N lcd(&i2c_lcd, ST7032_SA, TextLCD::LCD16x2, NC, TextLCD::ST7032_3V3); // I2C bus, Slaveaddress, LCD Type, BL=NC, LCDTCtrl=ST7032_3V3
int main() {
pc.printf("LCD Test. Columns=%d, Rows=%d\n\r", lcd.columns(), lcd.rows());
for (int row=0; row<lcd.rows(); row++) {
int col=0;
pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));
// lcd.putc('-');
lcd.putc('0' + row);
for (col=1; col<lcd.columns()-1; col++) {
lcd.putc('*');
}
pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));
lcd.putc('+');
}
// Show cursor as blinking character
lcd.setCursor(TextLCD::CurOff_BlkOn);
// Set and show user defined characters. A maximum of 8 UDCs are supported by the HD44780.
// They are defined by a 5x7 bitpattern.
lcd.setUDC(0, (char *) udc_0); // Show |>
lcd.putc(0);
lcd.setUDC(1, (char *) udc_1); // Show <|
lcd.putc(1);
}
Handbook page
More info is here
Revision 10:dd9b3a696acd, committed 2013-02-04
- Comitter:
- wim
- Date:
- Mon Feb 04 21:48:24 2013 +0000
- Parent:
- 9:0893d986e717
- Child:
- 11:9ec02df863a1
- Commit message:
- Added support for 24x4 LCDs using KS0078 controller; Added Cursor On/Off
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 Thu Jan 31 19:46:00 2013 +0000
+++ b/TextLCD.cpp Mon Feb 04 21:48:24 2013 +0000
@@ -42,10 +42,58 @@
writeByte(0x2); // 4-bit mode
wait(0.000040f); // most instructions take 40us
- writeCommand(0x28); // Function set 001 BW N F - -
- writeCommand(0x0C);
- writeCommand(0x06); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
- cls();
+ // Display is now in 4-bit mode
+ switch (_type) {
+ case LCD8x1:
+ writeCommand(0x20); // Function set 001 BW N F - -
+ // N=0 (1 line)
+ // F=0 (5x7 dots font)
+ break;
+
+ case LCD24x4:
+ // Special mode for KS0078
+ writeCommand(0x2A); // Function set 001 BW N RE DH REV
+ // N=1 (Dont care for KS0078)
+ // RE=0 (Extended Regs, special mode for KS0078)
+ // DH=1 (Disp shift, special mode for KS0078)
+ // REV=0 (Reverse, special mode for KS0078)
+
+ writeCommand(0x2E); // Function set 001 BW N RE DH REV
+ // N=1 (Dont care for KS0078)
+ // RE=1 (Ena Extended Regs, special mode for KS0078)
+ // DH=1 (Disp shift, special mode for KS0078)
+ // REV=0 (Reverse, special mode for KS0078)
+
+ writeCommand(0x09); // Ext Function set 0000 1 FW BW NW
+ // FW=0 (5-dot font, special mode for KS0078)
+ // BW=0 (Cur BW invert disable, special mode for KS0078)
+ // NW=1 (4 Line, special mode for KS0078)
+
+ writeCommand(0x2A); // Function set 001 BW N RE DH REV
+ // N=1 (Dont care for KS0078)
+ // RE=0 (Dis. Extended Regs, special mode for KS0078)
+ // DH=1 (Disp shift, special mode for KS0078)
+ // REV=0 (Reverse, special mode for KS0078)
+ break;
+
+ default:
+ writeCommand(0x28); // Function set 001 BW N F - -
+ // N=1 (2 lines)
+ // F=0 (5x7 dots font)
+
+ break;
+ }
+
+ writeCommand(0x0C); // Display Ctrl 0000 1 D C B
+ // Display On, Cursor Off, Blink Off
+ _cursor = CurOff;
+
+ writeCommand(0x06); // Entry Mode 0000 01 CD S
+ // Cursor Direction and Display Shift
+ // CD=1 (Cur incr)
+ // S=0 (No display shift)
+
+ cls();
}
@@ -184,6 +232,19 @@
return 0x54 + column;
}
+// Special mode for KS0078
+ case LCD24x4:
+ switch (row) {
+ case 0:
+ return 0x00 + column;
+ case 1:
+ return 0x20 + column;
+ case 2:
+ return 0x40 + column;
+ case 3:
+ return 0x60 + column;
+ }
+
// Not sure about this one, seems wrong.
case LCD16x2B:
return 0x00 + (row * 40) + column;
@@ -229,6 +290,7 @@
return 20;
case LCD24x2:
+ case LCD24x4:
return 24;
case LCD40x2:
@@ -255,9 +317,34 @@
case LCD16x4:
case LCD20x4:
+ case LCD24x4:
return 4;
default:
return 0;
}
}
+
+
+TextLCD::LCDCursor TextLCD::cursor(TextLCD::LCDCursor show) {
+ LCDCursor cur = _cursor;
+
+ switch (show) {
+ case CurOn : writeCommand(0x0F); // Cursor on and Blink char
+ wait_us(40);
+ _cursor = show;
+ break;
+ case CurOff : writeCommand(0x0C);
+ wait_us(40);
+ _cursor = show;
+ break;
+ default :
+ break;
+
+ }
+ return cur;
+}
+
+
+
+
--- a/TextLCD.h Thu Jan 31 19:46:00 2013 +0000
+++ b/TextLCD.h Mon Feb 04 21:48:24 2013 +0000
@@ -28,7 +28,7 @@
/** A TextLCD interface for driving 4-bit HD44780-based LCDs
*
- * Currently supports 8x1, 8x2, 16x2, 16x4, 20x2, 20x4, 24x2 and 40x2 panels
+ * Currently supports 8x1, 8x2, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
*
* @code
* #include "mbed.h"
@@ -42,6 +42,7 @@
* @endcode
*/
+
class TextLCD : public Stream {
public:
@@ -55,9 +56,17 @@
LCD20x2, /**< 20x2 LCD panel */
LCD20x4, /**< 20x4 LCD panel */
LCD24x2, /**< 24x2 LCD panel */
+ LCD24x4, /**< 24x4 LCD panel, special mode KS0078 */
LCD40x2 /**< 40x2 LCD panel */
};
+ /** LCD Cursor control */
+ enum LCDCursor {
+ CurOn,
+ CurOff
+ };
+
+
/** Create a TextLCD interface
*
* @param rs Instruction/data control line
@@ -89,17 +98,46 @@
*/
void locate(int column, int row);
+
+ /** Return the memoryaddress of screen column and row location
+ *
+ * @param column The horizontal position from the left, indexed from 0
+ * @param row The vertical position from the top, indexed from 0
+ * @param return The memoryaddress of screen column and row location
+ */
int getAddress(int column, int row);
+
+
+ /** Set the memoryaddress of screen column and row location
+ *
+ * @param column The horizontal position from the left, indexed from 0
+ * @param row The vertical position from the top, indexed from 0
+ */
void setAddress(int column, int row);
+ /** Set the Cursormode
+ *
+ * @param show The Cursor mode (CurOn or CurOff)
+ * @param return The current Cursor mode
+ */
+ LCDCursor cursor(LCDCursor show);
+
/** Clear the screen and locate to 0,0 */
void cls();
+ /** Return the number of rows
+ *
+ * @param return The number of rows
+ */
int rows();
- int columns();
+
+ /** Return the number of columns
+ *
+ * @param return The number of columns
+ */
+ int columns();
protected:
-
// Stream implementation functions
virtual int _putc(int value);
virtual int _getc();
@@ -116,6 +154,7 @@
int _column;
int _row;
+ LCDCursor _cursor;
};
#endif
HD44780 and compatible Text LCD controllers (4bit, I2C or SPI I/F)