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.cpp

Revision:
20:e0da005a777f
Parent:
19:c747b9e2e7b8
Child:
21:9eb628d9e164
--- a/TextLCD.cpp	Fri Apr 19 19:36:37 2013 +0000
+++ b/TextLCD.cpp	Mon May 13 19:29:13 2013 +0000
@@ -6,6 +6,7 @@
  *               2013, v04: WH, Added support for Display On/Off, improved 4bit bootprocess
  *               2013, v05: WH, Added support for 8x2B, added some UDCs   
  *               2013, v06: WH, Added support for devices that use internal DC/DC converters 
+ *               2013, v07: WH, Added support for backlight and include portdefinitions for LCD2004 Module from DFROBOT 
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -36,16 +37,17 @@
  * @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 bl     Backlight control line (optional, default = NC)  
  * @param e2     Enable2 line (clock for second controller, LCD40x4 only) 
  * @param ctrl   LCD controller (default = HD44780)   
  */ 
 TextLCD::TextLCD(PinName rs, PinName e,
                  PinName d4, PinName d5, PinName d6, PinName d7,
-                 LCDType type, PinName e2, LCDCtrl ctrl) : _rs(rs), _e(e), _e2(e2),
-                                                           _d(d4, d5, d6, d7),
-                                                           _cs(NC), 
-                                                           _type(type),
-                                                           _ctrl(ctrl) {
+                 LCDType type, PinName bl, PinName e2, LCDCtrl ctrl) : _rs(rs), _e(e), _bl(bl), _e2(e2),
+                                                                       _d(d4, d5, d6, d7),
+                                                                       _cs(NC), 
+                                                                       _type(type),
+                                                                       _ctrl(ctrl) {
 
   _busType = _PinBus;
 
@@ -61,7 +63,7 @@
  * @param ctrl            LCD controller (default = HD44780)    
  */
 TextLCD::TextLCD(I2C *i2c, char deviceAddress, LCDType type, LCDCtrl ctrl) :
-        _rs(NC), _e(NC), _e2(NC),
+        _rs(NC), _e(NC), _bl(NC), _e2(NC),
         _d(NC),
         _i2c(i2c),        
         _cs(NC),
@@ -90,7 +92,7 @@
   * @param ctrl            LCD controller (default = HD44780)      
   */
 TextLCD::TextLCD(SPI *spi, PinName cs, LCDType type, LCDCtrl ctrl) :
-        _rs(NC), _e(NC), _e2(NC),
+        _rs(NC), _e(NC), _bl(NC), _e2(NC),
         _d(NC),
         _spi(spi),        
         _cs(cs),
@@ -163,7 +165,7 @@
     // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)    
     for (int i=0; i<3; i++) {
         _writeNibble(0x3);
-        wait_ms(15);     // this command takes 1.64ms, so wait for it 
+        wait_ms(15);     // This command takes 1.64ms, so wait for it 
     }
     _writeNibble(0x2);   // 4-bit mode
     wait_us(40);         // most instructions take 40us
@@ -173,19 +175,19 @@
     
     // Device specific initialisations for DC/DC converter to generate VLCD or VLED
     switch (_ctrl) {
-      case ST7063:
+      case ST7036:
           // ST7036 controller: Initialise Voltage booster for VLCD. VDD=5V
           // Note: supports 1,2 or 3 lines
           _writeByte( 0x29 );    // 4-bit Databus, 2 Lines, Select Instruction table 1
-          wait_us(27);           // > 26,3ms 
+          wait_ms(30);           // > 26,3ms 
           _writeByte( 0x14 );    // Bias: 1/5, 2-Lines LCD 
-          wait_us(30);           // > 26,3ms
+          wait_ms(30);           // > 26,3ms
           _writeByte( 0x55 );    // Icon off, Booster on, Set Contrast C5, C4
-          wait_us(30);           // > 26,3ms
+          wait_ms(30);           // > 26,3ms
           _writeByte( 0x6d );    // Voltagefollower On, Ampl ratio Rab2, Rab1, Rab0
           wait_ms(200);          // > 200ms!
           _writeByte( 0x78 );    // Set Contrast C3, C2, C1, C0
-          wait_us(30);           // > 26,3ms
+          wait_ms(30);           // > 26,3ms
           _writeByte( 0x28 );    // Return to Instruction table 0
           wait_ms(50);
         
@@ -472,6 +474,48 @@
 
 }    
 
+// Set BL pin
+// Used for mbed pins, I2C bus expander or SPI shifregister
+void TextLCD::_setBL(bool value) {
+
+  switch(_busType) {
+    case _PinBus : 
+                    if (value)
+                      _bl  = 1;    // Set BL bit 
+                    else  
+                      _bl  = 0;    // Reset BL bit 
+
+                    break;  
+    
+    case _I2CBus : 
+                   if (value)
+                     _lcd_bus |= D_LCD_BL;    // Set BL bit 
+                   else                     
+                     _lcd_bus &= ~D_LCD_BL;   // Reset BL bit                     
+
+                   // write the new data to the I2C portexpander
+                   _i2c->write(_slaveAddress, &_lcd_bus, 1);    
+                   
+                   break;
+                       
+    case _SPIBus :
+                   if (value)
+                     _lcd_bus |= D_LCD_BL;    // Set BL bit 
+                   else                     
+                     _lcd_bus &= ~D_LCD_BL;   // Reset BL bit                     
+      
+                   // write the new data to the SPI portexpander
+                   _setCS(false);  
+                   _spi->write(_lcd_bus);   
+                   _setCS(true);  
+     
+                   break;
+  }
+
+}    
+
+
+
 // Place the 4bit data on the databus
 // Used for mbed pins, I2C bus expander or SPI shifregister
 void TextLCD::_setData(int value) {
@@ -931,6 +975,17 @@
     _writeCommand(0x08 | displayMode | cursorType);
 }
 
+// Set the Backlight mode (Off/On)
+void TextLCD::setBacklight(TextLCD::LCDBacklight backlightMode) {
+
+    if (backlightMode == LightOn) {
+      _setBL(true);
+    }
+    else {
+      _setBL(false);    
+    }
+} 
+
 
 void TextLCD::setUDC(unsigned char c, char *udc_data) {