/*
* LcdInit
* Description: This initializes the LCD. This must be called before the LCD can
* be used.
* Thus this function has to be called before calling any other
* LCD-interface functions.
* The LCD is set to the following specifications:
* 8-bit mode, 4-line display, 5x8 font
* cursor INCs, display doesn't shift
* cursor visible, cursor blinking
*
* Argument: None
* Return: None
*
* Input: None
* Output: LCD
*
* Operation:
* Really just follows standard initialization sequence. See sketch below
*
* POWER ON
* |
* | Wait time >40ms
* \|/
* FUNCTION SET (RS = 0, RW=0, DB = 0b0011NFXX) [BF cannot be checked b4 this]
* |
* | Wait time >37us
* \|/
* FUNCTION SET (RS = 0, RW=0, DB = 0b0011NFXX) [BF cannot be checked b4 this]
* |
* | Wait time >37us
* \|/
* DISPLAY ON/OFF control (RS = 0, RW=0, DB = 0b00001DCB)
* |
* | Wait time >37us
* \|/
* DISPLAY Clear (RS=0, RW=0, DB=0b00000001)
* |
* | Wait time >1.52ms
* \|/
* Entry Mode Set (RS=0, RW=0, DB=0b0000001{I/D}S)
* |
* | Wait time >37us
* \|/
* Initialization End
*
* Revision History:
* Dec. 16, 2012 Nnoduka Eruchalu Initial Revision
*/
void LcdInit(void)
{
LCD_DATA_TRIS = 0x00; /* setup LCD IO ports as outputs */
LCD_E_TRIS = 0;
LCD_RW_TRIS = 0;
LCD_RS_TRIS = 0;
LCD_DATA_LAT = 0; /* clear IO lines*/
CLEAR_RS(); CLEAR_RW(); CLEAR_E();
__delay_ms(40);
LCD_DATA_LAT = LCD_FUNC_SET; /* FUNCTION SET, done manually to prevent a */
LCD_STROBE(); /* BF check before next command */
__delay_us(40);
LcdCommand(LCD_FUNC_SET); /* FUNCTION SET, again done manually */
LCD_STROBE();
__delay_us(40);
LcdCommand(LCD_ON); /* DISPLAY ON/OFF control: Turn display on */
__delay_us(40);
LcdCommand(LCD_CLEAR); /* DISPLAY Clear */
__delay_ms(2);
LcdCommand(LCD_ENTRY_MD); /* ENTRY mode set */
GenSpecChars(); /* Now create some special characters */
}
//-------------------------------
void lcd_cmd(int8u_t data, int16u_t loop)
{/* LCD ELEMENTARY COMMAND */
HIGHBITS(data);
LCD_STROBE(0);
LOWBITS(data);
LCD_STROBE(loop); // busy delay
}
//-------------------------------
void lcd_cmd(int8u_t data)
{/* LCD ELEMENTARY COMMAND */
HIGHBITS(data);
LCD_STROBE(20);
LOWBITS(data);
LCD_STROBE(20); // busy delay
}
//-------------------------------
void lcd_config(int8u_t param)
{/* CONFIGURE THE DISPLAY */
HIGHBITS(param); // 4-bit, two lines, 5x8 pixel
LCD_STROBE(0); // change 8-bit interface to 4-bit interface
LCD_STROBE(0); // init 4-bit interface
LOWBITS(param);
LCD_STROBE(0);
}
/* initialize the LCD */
void
lcd_init(unsigned char mode)
{
char init_value;
fourbit = 0;
if (mode == FOURBIT_MODE){
fourbit = 1;
init_value = 0x30;
}else{
init_value = 0x3F;
}
LCD_RS = 0;
LCD_EN = 0;
LCD_RW = 0;
LCD_RS_TRIS = OUTPUT_PIN;
LCD_EN_TRIS = OUTPUT_PIN;
LCD_RW_TRIS = OUTPUT_PIN;
delay_ms(15);
if(fourbit){
LCD_DATA_TRIS = OUTPUT_PIN;
lcd_fourbit_cmd( init_value );
} else {
LCD_DATA_TRIS = OUTPUT_PIN;
LCD_DATA = init_value;
LCD_STROBE();
}
delay_ms(5);
if(!fourbit){
lcd_fourbit_cmd( init_value );
} else {
LCD_DATA = init_value;
LCD_STROBE();
}
delay_us(200);
if(!fourbit){
lcd_fourbit_cmd( init_value );
} else {
LCD_DATA = init_value;
LCD_STROBE();
}
if (fourbit){
LCD_WAIT; //may check LCD busy flag, or just delay a little, depending on lcd.h
lcd_fourbit_cmd( 0x20 );
lcd_cmd(0x28); // Function Set
}else{
lcd_cmd(0x38);
}
lcd_cmd(0xF); //Display On, Cursor On, Cursor Blink
lcd_cmd(0x1); //Display Clear
lcd_cmd(0x6); //Entry Mode
lcd_cmd(0x80); //Initialize DDRAM address to zero
}
/* Write a byte to the LCD in 4 bit mode */
void lcd_write(unsigned char c)
{ if(c & 0x80) LCD_D7=1; else LCD_D7=0;
if(c & 0x40) LCD_D6=1; else LCD_D6=0;
if(c & 0x20) LCD_D5=1; else LCD_D5=0;
if(c & 0x10) LCD_D4=1; else LCD_D4=0;
LCD_STROBE();
if(c & 0x08) LCD_D7=1; else LCD_D7=0;
if(c & 0x04) LCD_D6=1; else LCD_D6=0;
if(c & 0x02) LCD_D5=1; else LCD_D5=0;
if(c & 0x01) LCD_D4=1; else LCD_D4=0;
LCD_STROBE();
delay_50us();
}
/* send a command to the LCD */
void
lcd_cmd(unsigned char c)
{
LCD_WAIT; // may check LCD busy flag, or just delay a little, depending on lcd.h
if (fourbit) {
LCD_DATA = ( c & 0xF0 );
LCD_STROBE();
LCD_DATA = ( ( c << 4 ) & 0xF0 );
LCD_STROBE();
} else {
LCD_DATA = c;
LCD_STROBE();
}
}
/*
* LcdCommand
* Description: This procedure simply writes a command byte to the LCD.
* It does not return until the LCD's busy flag is cleared.
*
* Argument: c: command byte
* Return: None
*
* Input: None
* Output: LCD
*
* Operation: Send the byte, then wait for the BF to be cleared.
*
* Revision History:
* Dec. 16, 2012 Nnoduka Eruchalu Initial Revision
*/
void LcdCommand(unsigned char c)
{
LCD_DATA_LAT = c; /* put data on output port */
CLEAR_RS(); /* RS = 0: Command */
CLEAR_RW(); /* R/W = 0: Write */
LCD_STROBE();
LcdWaitBF(); /* dont exit until the LCD is no longer busy */
}
/* send data to the LCD */
void
lcd_data(unsigned char c) {
LCD_WAIT; // may check LCD busy flag, or just delay a little, depending on lcd.h
LCD_DATA = 0;
LCD_RS = 1;
if (fourbit) {
LCD_DATA = ( c & 0xF0 );
LCD_STROBE();
LCD_DATA &= 0x0F;
LCD_DATA = ( ( c << 4 ) & 0xF0 );
LCD_STROBE();
} else {
LCD_DATA = c;
LCD_STROBE();
}
LCD_RS = 0;
}
/* Initialise the LCD - put into 4 bit mode */
void lcd_init(void)
{ LCD_RS = 0;
LCD_EN = 0;
delay_100ms(); // Wait 100ms after power applied
LCD_D4 = 1;
LCD_D5 = 1;
LCD_STROBE();
delay_2ms(); // Wait 6ms
delay_2ms();
delay_2ms();
LCD_STROBE();
delay_2ms();
LCD_STROBE();
delay_2ms();
LCD_D4 = 0; // Set 4 bit mode
LCD_STROBE();
delay_50us();
lcd_cmd(0b00101000); // Set interface length 4-bit, 2-line, 5x8 dots display
lcd_cmd(0b00001100); // Display On, Cursor OFF, Cursor Blink OFF
lcd_cmd(0b00000110); // Set entry Mode
lcd_clear(); // Clear screen
}
void lcd_fourbit_cmd(unsigned char c){
LCD_DATA = ( c & 0xF0 ) | ( LCD_DATA & 0x0F );
LCD_STROBE();
}
