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A basic library for the Freetronics arduino LCD shield.

Dependents: freetronicsLCDShield_HelloWorld prototipo prototipo Juego

freetronicsLCDShield

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A library for the arduino targeted freetronics LCD shield (http://www.freetronics.com/products/lcd-keypad-shield#.UmzHGBDvfRU) This is my first attempt at publishing a library so bare with. The LCD is fully functional, the buttons however are not yet fully implemented.

Member functions

Constructor

freetronicsLCDShield (PinName rs, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, PinName bl, PinName a0);

Custom character generation

void writeCGRAM (char address, const char *ptr, char nbytes);

Characters that aren't included in the default character map can be written by the LCD controller 's character generator ram spaces (i.e. 0, 8, 16 .. 7 * 8). Each custom character consists of eight bytes in witch the lower 5 bits correspond to a pixel on the display. For example; the ° character witch isn't included in the default character map could be stored in the character generator RAM with:

<instanceName>.writeCGRAM(0, {0b00001100, 
                              0b00010010, 
                              0b00010010,
                              0b00001100,
                              0b00000000,
                              0b00000000,
                              0b00000000,
                              0b00000000}, 8);

Note: The binary values must be replaces by their corresponding hex or decimal values.

The ° character can now displayed by calling <instanceName>.putc(0) function.

Back-light control

void setBackLight (bool blStatus);
void setBackLight (float blIntensity);

Cursor control

void home(void);

The cursor returns home (i.e. the cursor is placed at 0,0), the screen is NOT cleared. Consecutive writes to the LCD overwrite the display.

void setCursorPosition (int line, int col);
void setCursor (bool cStatus = true, bool blink = false);

These are rather self-explanatory

Shift instructions

void shiftLeft (void);
void shiftRight (void); 
void shift (bool direction);

When direction is set the display shifts left, else it shifts right

Clearing the display

void cls (void);

Button support

float readButton(void);

There is rather limited button support, you can read the status of the button pin as a float value.

Hello world

#include "mbed.h"
#include "freetronicsLCDShield.h"

// These are the custom chars 8 of them 1 per row.
const char CGRAM_DATA[64]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x1F,
                           0x00,0x00,0x00,0x00,0x00,0x00,0x1F,0x1F,
                           0x00,0x00,0x00,0x00,0x00,0x1F,0x1F,0x1F,
                           0x00,0x00,0x00,0x00,0x1F,0x1F,0x1F,0x1F,
                           0x00,0x00,0x00,0x1F,0x1F,0x1F,0x1F,0x1F,
                           0x00,0x00,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,
                           0x00,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,
                           0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F};

/* freetronicsLCDShield LCD(rs, e, d0, d1, d2, d3, bl, a0); */
freetronicsLCDShield LCD(PTA13, PTD5, PTA4, PTA5, PTC8, PTC9, PTA12, PTB0);
 
int main() {
    // Write custom generated chars to the 
    LCD.writeCGRAM (0x00, &CGRAM_DATA[0], 8);
    LCD.writeCGRAM (0x08, &CGRAM_DATA[8], 8);
    LCD.writeCGRAM (0x10, &CGRAM_DATA[16], 8);
    LCD.writeCGRAM (0x18, &CGRAM_DATA[24], 8);
    LCD.writeCGRAM (0x20, &CGRAM_DATA[32], 8);
    LCD.writeCGRAM (0x28, &CGRAM_DATA[40], 8);
    LCD.writeCGRAM (0x30, &CGRAM_DATA[48], 8);
    LCD.writeCGRAM (0x38, &CGRAM_DATA[56], 8);
    
    LCD.cls();
    
    // The backlight can be turned on or off //
    LCD.setBackLight(true); wait(2.0); 
    // The setBackLight method is overloaded so you can specify it's intensity by supplying it with a float value
    LCD.setBackLight((float) 0.05);
    
    while (true) {
        LCD.cls();
        LCD.setCursor(false);
        // You may want to set the cursor position at a specific location
        LCD.setCursorPosition (0, 0);
        LCD.printf("* Hello  world *");
    
        // Shift the text on the LCD left ...
        for(int i = 0; i < 3; i++) {LCD.shift(true); wait(0.5);}
        
        // Shift right ...
        for(int i = 0; i < 6; i++) {LCD.shift(false); wait(0.5);}
        
        // Shift the text back to left ...
        for(int i = 0; i < 3; i++) {LCD.shift(true); wait(0.5);}
        
        LCD.setCursorPosition (1,0);
        // Let the cursor blink 
        LCD.setCursor(true, true);
        LCD.putc('A'); wait(0.5);    
        LCD.putc('w'); wait(0.5);     
        LCD.putc('e'); wait(0.5);    
        LCD.putc('s'); wait(0.5);    
        LCD.putc('o'); wait(0.5);    
        LCD.putc('m'); wait(0.5);    
        LCD.putc('e'); wait(0.5);    
        
        LCD.cls();
        LCD.setCursor(false);
        // You may want to set the cursor position at a specific location
        LCD.setCursorPosition (0, 0);
        LCD.printf("Backlight = %0.3f", 0.000);
        int n = 0;

        for (float intensity = 0.125; intensity <= 1.0; intensity += 0.125) {
           // Fire up the backlight 
            LCD.setBackLight((float) intensity);
            // Display intensity
            LCD.setCursorPosition(0,11);
            LCD.printf("%0.3f", intensity);
            
            // Print the custom char's 0 .. 7
            LCD.setCursorPosition(1,4+n);
            LCD.putc(n);
            n++;
            wait(0.5);
        } 
   }
}

Picture

/media/uploads/KKempeneers/sv105343.jpg