Wim Huiskamp / TextLCD

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

Fork of 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

Diff: TextLCD.h

Revision:
15:b70ebfffb258
Parent:
14:0c32b66b14b8
Child:
16:c276b75e6585
--- a/TextLCD.h	Sun Feb 10 18:43:51 2013 +0000
+++ b/TextLCD.h	Tue Feb 19 22:09:09 2013 +0000
@@ -1,7 +1,8 @@
 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
  * Copyright (c) 2007-2010, sford, http://mbed.org
  *               2013, v01: WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs 
- *               2013, v02: WH, Added I2C and SPI bus interfaces 
+ *               2013, v02: WH, Added I2C and SPI bus interfaces
+ *               2013, v03: WH, Added support for LCD40x4 which uses 2 controllers   
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -27,15 +28,20 @@
 
 #include "mbed.h"
 
+
+//Test Only
+//#define LCD40x4Test 0
+#define LCD40x4Test 1
+
 /** A TextLCD interface for driving 4-bit HD44780-based LCDs
  *
- * Currently supports 8x1, 8x2, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
+ * Currently supports 8x1, 8x2, 12x4, 16x1, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
  *
  * @code
  * #include "mbed.h"
  * #include "TextLCD.h"
  * 
- * TextLCD lcd(p15, p16, p17, p18, p19, p20); // RS, E, D4-D7 
+ * TextLCD lcd(p15, p16, p17, p18, p19, p20); // RS, E, D4-D7, LCDType=LCD16x2
  * 
  * int main() {
  *     lcd.printf("Hello World!\n");
@@ -47,19 +53,20 @@
 //Pin Defines for I2C PCF8574 and SPI 74595 Bus
 //LCD and serial portexpanders should be wired accordingly 
 //Note: LCD RW pin must be connected to GND
-//      E2 may be used for future expansion to LCD40x4
+//      E2 is used for LCD40x4 (second controller)
 //      BL may be used for future expansion to control backlight
 //
-#define D_LCD_PIN_D4   0x00
-#define D_LCD_PIN_D5   0x01
-#define D_LCD_PIN_D6   0x02
-#define D_LCD_PIN_D7   0x03
-#define D_LCD_PIN_RS   0x04
-#define D_LCD_PIN_E    0x05
-#define D_LCD_PIN_E2   0x06
-#define D_LCD_PIN_BL   0x07
+#define D_LCD_PIN_D4   0
+#define D_LCD_PIN_D5   1
+#define D_LCD_PIN_D6   2
+#define D_LCD_PIN_D7   3
+#define D_LCD_PIN_RS   4
+#define D_LCD_PIN_E    5
+#define D_LCD_PIN_E2   6
+#define D_LCD_PIN_BL   7
 
 #define D_LCD_BUS_MSK  0x0F
+#define D_LCD_BUS_DEF  0x00
 
 //Bitpattern Defines for I2C PCF8574 and SPI 74595 Bus
 //
@@ -112,7 +119,7 @@
 
 /** A TextLCD interface for driving 4-bit HD44780-based LCDs
  *
- * Currently supports 8x1, 8x2, 16x1, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
+ * Currently supports 8x1, 8x2, 12x4, 16x1, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4, 40x2 and 40x4 panels
  *
  */
 class TextLCD : public Stream {
@@ -122,6 +129,8 @@
     enum LCDType {
         LCD8x1,     /**<  8x1 LCD panel */    
         LCD8x2,     /**<  8x2 LCD panel */          
+        LCD12x2,    /**< 12x2 LCD panel */                          
+        LCD12x4,    /**< 12x4 LCD panel */                  
         LCD16x1,    /**< 16x1 LCD panel (actually 8x2) */          
         LCD16x2,    /**< 16x2 LCD panel (default) */
         LCD16x2B,   /**< 16x2 LCD panel alternate addressing */
@@ -130,7 +139,8 @@
         LCD20x4,    /**< 20x4 LCD panel */
         LCD24x2,    /**< 24x2 LCD panel */        
         LCD24x4,    /**< 24x4 LCD panel, special mode KS0078 */                
-        LCD40x2     /**< 40x2 LCD panel */                
+        LCD40x2,    /**< 40x2 LCD panel */                
+        LCD40x4     /**< 40x4 LCD panel, Two controller version */                        
     };
 
     /** LCD Cursor control */
@@ -142,14 +152,15 @@
     };
 
 
-    /** Create a TextLCD interface for using regural mbed pins
+    /** Create a TextLCD interface for using regular mbed pins
      *
      * @param rs    Instruction/data control line
      * @param e     Enable line (clock)
      * @param d4-d7 Data lines for using as a 4-bit interface
      * @param type  Sets the panel size/addressing mode (default = LCD16x2)
+     * @param e2    Enable2 line (clock for second controller, LCD40x4 only)      
      */
-    TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2);
+    TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2, PinName e2 = NC);
     
     /** Create a TextLCD interface using an I2C PC8574 portexpander
      *
@@ -243,17 +254,32 @@
     enum _LCDBus {
         _PinBus,  /*<  Regular mbed pins */    
         _I2CBus,  /*<  I2C PCF8574 Portexpander */    
-        _SPIBus   /*<  SPI 74595 */    
+        _SPIBus   /*<  SPI 74595 Shiftregister */    
     };
 
+   /* LCD controller select, mainly used for LCD40x4 */
+    enum _LCDCtrl {
+        _LCDCtrl_0,  /*<  Primary */    
+        _LCDCtrl_1,  /*<  Secondary */            
+    };
+    
     // Stream implementation functions
     virtual int _putc(int value);
     virtual int _getc();
 
+//Low level methods for LCD controller
     void _init();    
+    void _initCtrl();    
     int  _address(int column, int row);
     void _character(int column, int row, int c);
+    void _setCursor(TextLCD::LCDCursor show);
+    void _setUDC(unsigned char c, char *udc_data);     
     
+//Low level write operations to LCD controller
+    void _writeByte(int value);
+    void _writeCommand(int command);
+    void _writeData(int data);
+
 //Low level writes to LCD Bus (serial or parallel)
     void _setEnable(bool value);
     void _setRS(bool value);  
@@ -263,13 +289,9 @@
 //Low level writes to LCD serial bus only
     void _writeBus();      
 
-//Low level writes to LCD
-    void _writeByte(int value);
-    void _writeCommand(int command);
-    void _writeData(int data);
   
 // Regular mbed pins bus
-    DigitalOut _rs, _e;
+    DigitalOut _rs, _e, _e2;
     BusOut _d;
     
 // I2C bus    
@@ -283,16 +305,19 @@
 //Bus Interface type    
     _LCDBus _busType;
 
-// Internal bus mirror value for serial only
+// Internal bus mirror value for serial bus only
     char _lcd_bus;   
     
 //Display type
     LCDType _type;
 
+//Controller select, mainly used for LCD40x4 
+    _LCDCtrl _ctrl;    
+
 // Cursor
     int _column;
     int _row;
-    LCDCursor _cursor;    
+    LCDCursor _currentCursor;    
 };
 
 #endif