From 3f358c19e5fe1d48285c4a9b3930a942f2f866fe Mon Sep 17 00:00:00 2001
From: Vineet K <git@vineetk.net>
Date: Sat, 20 Apr 2024 15:42:35 -0400
Subject: import lcd.c from lab 10

---
 lcd.c | 180 ++++++++++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 109 insertions(+), 71 deletions(-)

diff --git a/lcd.c b/lcd.c
index 6d9bd4a..5b8866a 100644
--- a/lcd.c
+++ b/lcd.c
@@ -1,89 +1,127 @@
-#include <avr/io.h>
-
-#define F_CPU	16000000UL
-#include <util/delay.h>
-
-// Define LCD control pin connections
-#define LCD_RS_PIN	PB0
-#define LCD_RW_PIN	PB1
-#define LCD_E_PIN	PB2
-#define LCD_RS_PORT	PORTB
-#define LCD_RW_PORT	PORTB
-#define LCD_E_PORT	PORTB
-// Define LCD data pin connections
-#define LCD_DATA_PORT	PORTD
-#define LCD_DATA_DDR	DDRD
-
-// Function prototypes
-void LCD_init();
-void LCD_command(uint8_t cmd);
-void LCD_write(uint8_t data);
-void LCD_send(char* str);
-
-int
-main()
-{
-	// Set control pins as outputs
-	DDRB |= (1 << LCD_RS_PIN) | (1 << LCD_RW_PIN) | (1 << LCD_E_PIN);
-	// Set data pins as outputs
-	LCD_DATA_DDR = 0xFF;
+#include <avr/io.h>    //standard AVR header
 
-	// Initialize LCD
-	LCD_init();
+#define F_CPU 16000000UL	// THE CPU FREQUENCY 
+#include <util/delay.h>		//delay header
 
-	// Display "Hello, World!"
-	LCD_send("Hello, World!");
+#define	LCD_DPRT	PORTD 	//LCD DATA PORT	
+#define	LCD_DDDR	DDRD	//LCD DATA DDR
+#define	LCD_DPIN	PIND	//LCD DATA PIN
+#define	LCD_CPRT	PORTB	//LCD COMMANDS PORT
+#define	LCD_CDDR	DDRB	//LCD COMMANDS DDR
+#define	LCD_CPIN	PINB	//LCD COMMANDS PIN
+#define	LCD_RS  0		//LCD RS
+#define	LCD_EN  1		//LCD EN
 
-	for (;;) {
-		// Your main code here
-	}
+void lcd_putValue(unsigned char val){
+	LCD_DPRT &= 0x0F;
+	LCD_DPRT |= (val&0xF0);		//send cmnd to data port
+	LCD_CPRT |= (1<<LCD_EN);		//EN = 1 for H-to-L pulse
+	_delay_us(1);				//wait to make enable wide
+	LCD_CPRT &= ~ (1<<LCD_EN);	//EN = 0 for H-to-L pulse
+	_delay_us(100);			//wait to make enable wide
 
-	return 0;
+	LCD_DPRT &= 0x0F;
+	LCD_DPRT |= val<<4;			//send cmnd to data port
+	LCD_CPRT |= (1<<LCD_EN);		//EN = 1 for H-to-L pulse
+	_delay_us(1);				//wait to make enable wide
+	LCD_CPRT &= ~ (1<<LCD_EN);	//EN = 0 for H-to-L pulse
+	_delay_us(100);			//wait to make enable wide  	
 }
 
-// Initialize LCD
-void
-LCD_init()
+//*******************************************************
+void lcdCommand( unsigned char cmnd ){	
+	LCD_CPRT &= ~ (1<<LCD_RS);		//RS = 0 for command	
+	lcd_putValue(cmnd);
+}
+
+//*******************************************************
+void lcdData( unsigned char data )
 {
-	_delay_ms(15);		// Delay for power-on
-	LCD_command(0x38);	// Function Set: 8-bit data, 2-line display, 5x8 font
-	LCD_command(0x0C);	// Display ON, Cursor OFF, Blink OFF
-	LCD_command(0x01);	// Clear display
-	_delay_ms(2);		// Delay for Clear Display command
-	LCD_command(0x06);	// Entry Mode Set: Increment cursor, No display shift
+	LCD_CPRT |= (1<<LCD_RS);		//RS = 1 for data 	
+	lcd_putValue(data);	 
 }
 
-// Send command to LCD
-void
-LCD_command(uint8_t cmd)
+void lcd_clear()
 {
-	LCD_RS_PORT &= ~(1 << LCD_RS_PIN);	// Set RS low for command mode
-	LCD_RW_PORT &= ~(1 << LCD_RW_PIN);	// Set RW low for write mode
-	LCD_DATA_PORT = cmd;			// Send command to data port
-	LCD_E_PORT |= (1 << LCD_E_PIN);		// Enable LCD
-	_delay_us(1);				// Short delay
-	LCD_E_PORT &= ~(1 << LCD_E_PIN);	// Disable LCD
-	_delay_us(100);				// Delay for command execution
+	lcdCommand(0x01);	
+	_delay_us(1700);
 }
 
-// Write data to LCD
-void
-LCD_write(uint8_t data)
+void lcd_showCursor()
 {
-	LCD_RS_PORT |= (1 << LCD_RS_PIN);	// Set RS high for data mode
-	LCD_RW_PORT &= ~(1 << LCD_RW_PIN);	// Set RW low for write mode
-	LCD_DATA_PORT = data;			// Send data to data port
-	LCD_E_PORT |= (1 << LCD_E_PIN);		// Enable LCD
-	_delay_us(1);				// Short delay
-	LCD_E_PORT &= ~(1 << LCD_E_PIN);	// Disable LCD
-	_delay_us(100);				// Delay for data execution
+	lcdCommand(0x0E);
+	_delay_us(50);
 }
 
-// Send string to LCD
-void
-LCD_send(char *str)
+void lcd_hideCursor()
 {
-	while (*str)
-		LCD_write(*str++);
+	lcdCommand(0x0C);
+	_delay_us(50);
 }
 
+//*******************************************************
+void lcd_init()
+{
+	LCD_DDDR |= 0xF0;
+	LCD_CDDR |= (1<<LCD_RS)|(1<<LCD_EN);
+ 
+	LCD_CPRT &=~(1<<LCD_EN);	//LCD_EN = 0
+	_delay_us(2000);	//wait for init.
+
+	lcdCommand(0x33);	//send $33 for init.
+	lcdCommand(0x32);	//send $32 for init
+	lcdCommand(0x28);	//init. LCD 2 line,5*7 matrix
+	lcdCommand(0x0e);	//display on, cursor on
+	lcdCommand(0x06);	//shift cursor right
+
+	lcd_clear();		
+}
+
+//*******************************************************
+void lcd_gotoxy(unsigned char x, unsigned char y)
+{  
+	unsigned char firstCharAdr[]={0x80,0xC0,0x94,0xD4};//Table 12-4  
+	lcdCommand(firstCharAdr[y-1] + x - 1);
+	_delay_us(100);	
+}
+
+//*******************************************************
+void lcd_print( char * str )
+{
+	unsigned char i = 0;
+
+	while(str[i] != 0) //while it is not end of string
+	{
+		lcdData(str[i]);
+		i++ ;
+	}
+}
+
+//*******************************************************
+int main(void) 
+{	
+	lcd_init();
+	lcd_hideCursor();
+	
+	while(1)
+	{	
+		lcd_clear();
+		lcd_gotoxy(1,1);
+		lcd_print("The world is but");
+		lcd_gotoxy(1,2);
+		lcd_print("one country");
+
+		lcd_showCursor();
+		_delay_ms(2500);
+	
+		lcd_clear();
+	
+		lcd_gotoxy(1,1);
+		lcd_print("and mankind its");
+		lcd_gotoxy(1,2);
+		lcd_print("citizens.");	
+		_delay_ms(3500);	
+	}
+
+	return 0;
+}
\ No newline at end of file
-- 
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