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:
13:24506ba22480
Parent:
12:6bf9d9957d31
Child:
14:0c32b66b14b8
--- a/TextLCD.h	Tue Feb 05 21:50:43 2013 +0000
+++ b/TextLCD.h	Sat Feb 09 15:10:36 2013 +0000
@@ -1,6 +1,7 @@
 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
  * Copyright (c) 2007-2010, sford, http://mbed.org
- *               2013, WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs 
+ *               2013, v01: WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs 
+ *               2013, v02: WH, Added I2C and SPI bus interfaces 
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -42,7 +43,38 @@
  * @endcode
  */
 
-/** User Defined Chars 5x7 dots */
+
+//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
+//      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_BUS_MSK  0x0F
+
+//Bitpattern Defines for I2C PCF8574 and SPI 74595 Bus
+//
+#define D_LCD_D4       (1<<D_LCD_PIN_D4)
+#define D_LCD_D5       (1<<D_LCD_PIN_D5)
+#define D_LCD_D6       (1<<D_LCD_PIN_D6)
+#define D_LCD_D7       (1<<D_LCD_PIN_D7)
+#define D_LCD_RS       (1<<D_LCD_PIN_RS)
+#define D_LCD_E        (1<<D_LCD_PIN_E)
+#define D_LCD_E2       (1<<D_LCD_PIN_E2)
+#define D_LCD_BL       (1<<D_LCD_PIN_BL)
+
+
+
+/** Some sample User Defined Chars 5x7 dots */
 const char udc_ae[] = {0x00, 0x00, 0x1B, 0x05, 0x1F, 0x14, 0x1F, 0x00};  //æ
 const char udc_0e[] = {0x00, 0x00, 0x0E, 0x13, 0x15, 0x19, 0x0E, 0x00};  //ø
 const char udc_ao[] = {0x0E, 0x0A, 0x0E, 0x01, 0x0F, 0x11, 0x0F, 0x00};  //å
@@ -59,10 +91,28 @@
 const char udc_6[]  = {0x15, 0x0a, 0x15, 0x0a, 0x15, 0x0a, 0x15, 0x00};  // checkerboard
 const char udc_7[]  = {0x10, 0x08, 0x04, 0x02, 0x01, 0x00, 0x10, 0x00};  // \
 
+const char udc_degr[]   = {0x06, 0x09, 0x09, 0x06, 0x00, 0x00, 0x00, 0x00};  // Degree symbol
+
+const char udc_TM_T[]   = {0x1F, 0x04, 0x04, 0x04, 0x00, 0x00, 0x00, 0x00};  // Trademark T
+const char udc_TM_M[]   = {0x11, 0x1B, 0x15, 0x11, 0x00, 0x00, 0x00, 0x00};  // Trademark M
+
+//const char udc_Bat_Hi[] = {0x0E, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Full
+//const char udc_Bat_Ha[] = {0x0E, 0x11, 0x13, 0x17, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Half
+//const char udc_Bat_Lo[] = {0x0E, 0x11, 0x11, 0x11, 0x11, 0x11, 0x1F, 0x00};  // Battery Low
+const char udc_Bat_Hi[] = {0x0E, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Full
+const char udc_Bat_Ha[] = {0x0E, 0x11, 0x11, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Half
+const char udc_Bat_Lo[] = {0x0E, 0x11, 0x11, 0x11, 0x11, 0x1F, 0x1F, 0x00};  // Battery Low
+
+const char udc_bar_1[]  = {0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00};  // Bar 1
+const char udc_bar_2[]  = {0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x00};  // Bar 11
+const char udc_bar_3[]  = {0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x00};  // Bar 111
+const char udc_bar_4[]  = {0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x00};  // Bar 1111
+const char udc_bar_5[]  = {0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Bar 11111
+
 
 /** 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, 16x1, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
  *
  */
 class TextLCD : public Stream {
@@ -71,7 +121,8 @@
     /** LCD panel format */
     enum LCDType {
         LCD8x1,     /**<  8x1 LCD panel */    
-        LCD8x2,     /**<  8x2 LCD panel */            
+        LCD8x2,     /**<  8x2 LCD panel */          
+        LCD16x1,    /**< 16x1 LCD panel (actually 8x2) */          
         LCD16x2,    /**< 16x2 LCD panel (default) */
         LCD16x2B,   /**< 16x2 LCD panel alternate addressing */
         LCD16x4,    /**< 16x4 LCD panel */        
@@ -91,7 +142,7 @@
     };
 
 
-    /** Create a TextLCD interface
+    /** Create a TextLCD interface for using regural mbed pins
      *
      * @param rs    Instruction/data control line
      * @param e     Enable line (clock)
@@ -99,6 +150,24 @@
      * @param type  Sets the panel size/addressing mode (default = LCD16x2)
      */
     TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2);
+    
+    /** Create a TextLCD interface using an I2C PC8574 portexpander
+     *
+     * @param i2c             I2C Bus
+     * @param deviceAddress   I2C slave address (PCF8574)
+     * @param type            Sets the panel size/addressing mode (default = LCD16x2)
+     */
+    TextLCD(I2C *i2c, char deviceAddress, LCDType type = LCD16x2);
+
+
+    /** Create a TextLCD interface using an SPI 74595 portexpander
+     *
+     * @param spi             SPI Bus
+     * @param cs              chip select pin (active low)
+     * @param type            Sets the panel size/addressing mode (default = LCD16x2)
+     */
+//    TextLCD(SPI *spi, PinName cs, LCDType type = LCD16x2);
+
 
 #if DOXYGEN_ONLY
     /** Write a character to the LCD
@@ -159,7 +228,7 @@
      *
      * @param show    The Cursor mode (CurOff_BlkOff, CurOn_BlkOff, CurOff_BlkOn, CurOn_BlkOn)
      */
-    void cursor(LCDCursor show);     
+    void setCursor(LCDCursor show);     
 
 
     /** Set User Defined Characters
@@ -170,20 +239,56 @@
     void setUDC(unsigned char c, char *udc_data);
 
 protected:
+   /** LCD Bus control */
+    enum _LCDBus {
+        _PinBus,  /**<  Regular mbed pins */    
+        _I2CBus,  /**<  I2C PCF8574 Portexpander */    
+        _SPIBus   /**<  SPI 74595 */    
+    };
+
     // Stream implementation functions
     virtual int _putc(int value);
     virtual int _getc();
 
-    int  address(int column, int row);
-    void character(int column, int row, int c);
-    void writeByte(int value);
-    void writeCommand(int command);
-    void writeData(int data);
+    void _init();    
+    int  _address(int column, int row);
+    void _character(int column, int row, int c);
+    
+//Low level writes to LCD Bus (serial or parallel)
+    void _setEnable(bool value);
+    void _setRS(bool value);  
+    void _setData(int value);
 
+//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;
     BusOut _d;
+    
+// I2C bus    
+    I2C *_i2c;
+    unsigned char _slaveAddress;
+    
+// SPI bus        
+//    SPI *_spi;
+//    DigitalOut _cs;    
+    
+//Bus Interface type    
+    _LCDBus _busType;
+
+// Internal bus mirror value for serial only
+    char _lcd_bus;   
+    
+//Display type
     LCDType _type;
 
+// Cursor
     int _column;
     int _row;
     LCDCursor _cursor;