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:
2:227356c7d12c
Parent:
1:ac48b187213c
Child:
3:2a46d5820a78
--- a/TextLCD.h	Thu May 27 13:44:15 2010 +0000
+++ b/TextLCD.h	Thu May 27 17:52:15 2010 +0000
@@ -7,10 +7,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *  
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *  
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -24,48 +24,90 @@
 #define MBED_TEXTLCD_H
 
 #include "mbed.h"
+
+/** A TextLCD interface for 4-bit HD44780-based LCDs
+ *
+ * Supports a number of different panel configurations
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "TextLCD.h"
+ *
+ * TextLCD lcd(p5, p6, p7, p8, p9);
+ *
+ * int main() {
+ *     lcd.printf("Hello World!\n");
+ * }
+ * @endcode
+ */
 class TextLCD : public Stream {
 public:
 
-    // the different LCDs and addressing modes
-    /** Select the type of LCD */
+    /** LCD panel format */
     enum LCDType {
-        LCD16x2
-        , LCD16x2B
-        , LCD20x2
-        , LCD20x4
+        LCD16x2     /**< 16x2 LCD panel (default) */
+        , LCD16x2B  /**< 16x2 LCD panel alternate addressing */
+        , LCD20x2   /**< 20x2 LCD panel */
+        , LCD20x4   /**< 20x4 LCD panel */
     };
 
+    /** Create a TextLCD interface
+     *
+     * @param rs    Instruction/data control line
+     * @param e     Enable line (clock)
+     * @param d0-d3 Data lines
+     * @param type  Sets the panel size/addressing mode (default = LCD16x2)
+     */
     TextLCD(PinName rs, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, LCDType type = LCD16x2);
-    // int putc(int c) inherited from Stream
-    // int printf(...) inherited from Stream
-    void character(int column, int row, int c);
+
+#if DOXYGEN_ONLY
+    /** Write a character to the LCD
+     *
+     * @param c The character to write to the display
+     */
+    int putc(int c);
+
+    /** Write a formated string to the LCD
+     *
+     * @param format A printf-style format string, followed by the
+     *               variables to use in formating the string.
+     */
+    int printf(const char* format, ...);
+#endif
+
+    /** Locate to a screen column and row
+     *
+     * @param column  The horizontal position from the left, indexed from 0
+     * @param row     The vertical position from the top, indexed from 0
+     */
     void locate(int column, int row);
+
+    /** Clear the screen and locate to 0,0 */
     void cls();
-    
+
     int rows();
-    int columns();  
-    
-    
+    int columns();
+
 protected:
 
     // Stream implementation functions
     virtual int _putc(int value);
     virtual int _getc();
 
-    // internal tx functions
+    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);
-    int address(int column, int row);
 
     DigitalOut _rs, _e;
     BusOut _d;
     LCDType _type;
 
-    // current row/column
     int _column;
     int _row;
 };
 
+}
+
 #endif