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:
2:227356c7d12c
Parent:
1:ac48b187213c
Child:
4:bf5b706f8d32
--- a/TextLCD.cpp	Thu May 27 13:44:15 2010 +0000
+++ b/TextLCD.cpp	Thu May 27 17:52:15 2010 +0000
@@ -23,33 +23,6 @@
 #include "TextLCD.h"
 #include "mbed.h"
 
-/* useful info found at http://www.a-netz.de/lcd.en.php
- *
- * Initialisation
- * ==============
- *
- * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state
- *
- * - wait approximately 15 ms so the display is ready to execute commands
- * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now).
- * - The display is in 8 bit mode, so if you have only connected 4 data pins you should only transmit the higher nibble of each command.
- * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now.
- * - Execute the "clear display" command
- *
- * Timing
- * ======
- *
- * Nearly all commands transmitted to the display need 40us for execution.
- * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position"
- * These commands need 1.64ms for execution. These timings are valid for all displays working with an
- * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you
- * can use the busy flag to test if the display is ready to accept the next command.
- *
- * _e is kept high apart from calling clock
- * _rw is kept 0 (write) apart from actions that uyse it differently
- * _rs is set by the data/command writes
- */
-
 TextLCD::TextLCD(PinName rs, PinName e, PinName d0, PinName d1,
                  PinName d2, PinName d3, LCDType type) : _rs(rs),
         _e(e), _d(d0, d1, d2, d3),