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:
18:bd65dc10f27f
Parent:
17:652ab113bc2e
Child:
19:c747b9e2e7b8
--- a/TextLCD.cpp	Sat Mar 02 16:51:01 2013 +0000
+++ b/TextLCD.cpp	Sat Mar 09 19:39:53 2013 +0000
@@ -3,7 +3,8 @@
  *               2013, v01: WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs 
  *               2013, v02: WH, Added I2C and SPI bus interfaces  
  *               2013, v03: WH, Added support for LCD40x4 which uses 2 controllers 
- *               2013, v04: WH, Added support for Display On/Off, improved 4bit bootprocess 
+ *               2013, v04: WH, Added support for Display On/Off, improved 4bit bootprocess
+ *               2013, v05: WH, Added support for 8x2B, added some UDCs   
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -172,10 +173,32 @@
     _writeByte(0x2);     // 4-bit mode
     wait_us(40);         // most instructions take 40us
 #endif
+
+    // Display is now in 4-bit mode
+
+#if(0)
+    // 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 
+    _writeByte( 0x14 );    // Bias: 1/5, 2-Lines LCD 
+    wait_us(30);           // > 26,3ms
+    _writeByte( 0x55 );    // Icon off, Booster on, Set Contrast C5, C4
+    wait_us(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
+    _writeByte( 0x28 );    // Return to Instruction table 0
+    wait_ms(50);
+#endif
     
-    // Display is now in 4-bit mode
+    // Initialise Display configuration
     switch (_type) {
         case LCD8x1:
+        case LCD8x2B:        
+            //8x1 is a regular 1 line display
+            //8x2B is a special case of 16x1
             _writeCommand(0x20); // Function set 001 DL N F - -
                                  //  DL=0 (4 bits bus)             
                                  //   N=0 (1 line)
@@ -611,7 +634,15 @@
     switch (_type) {
         case LCD8x1:
             return 0x00 + column;                        
-    
+
+        case LCD8x2B:
+            // LCD8x2B is a special layout of LCD16x1
+            if (row==0) 
+              return 0x00 + column;                        
+            else   
+              return 0x08 + column;                        
+
+
         case LCD16x1:
             // LCD16x1 is a special layout of LCD8x2
             if (column<8) 
@@ -672,7 +703,7 @@
         case LCD16x2B:      
             return 0x00 + (row * 40) + column;
       
-        case LCD8x2:        
+        case LCD8x2:               
         case LCD12x2:                
         case LCD16x2:
         case LCD20x2:
@@ -756,6 +787,7 @@
     switch (_type) {
         case LCD8x1:
         case LCD8x2:
+        case LCD8x2B:                
             return 8;
         
         case LCD12x2:        
@@ -793,6 +825,7 @@
             return 1;           
 
         case LCD8x2:  
+        case LCD8x2B:                        
         case LCD12x2:                      
         case LCD16x2:
         case LCD16x2B: