/*
 * Analog Voltmeter
 *
 * Created: 12/1/2023 1:29:09 PM
 * Author : VGU1
 */ 
#include <stdio.h>
#define F_CPU 8000000UL
#include <avr/io.h>						/* Include AVR std. library file */
#include <util/delay.h>					/* Include inbuilt defined Delay header file */


#define RS PB3							/* Define Register Select (data reg./command reg.) signal pin */
#define EN PB2 							/* Define Enable signal pin */
#define lcd_port PORTB
#define lcd_ddr  DDRB
#define analog_port PORTA
#define analog_ddr DDRA
float volt;

void ADC_Init(){
	PORTA = 0x00;          /* Make ADC port as input */
	ADCSRA |= (1<<ADEN)|(1<<ADIE)|(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS1);          /* Enable ADC, with freq/128  */
	// ADMUX |= (1<<REFS0);           /* Vref: Avcc, ADC channel: 0 */
}

int ADC_Read(char channel)
{
	ADMUX |= (channel & 0x07);   /* set input channel to read */
	ADCSRA |= (1<<ADSC);               /* Start ADC conversion */
	while (!(ADCSRA & (1<<ADIF)));     /* Wait until end of conversion by polling ADC interrupt flag */
	ADCSRA |= (1<<ADIF);               /* Clear interrupt flag */
  	_delay_ms(1);                      /* Wait a little bit */
	return ADCW;                       /* Return ADC word */
}

void lcd_sending_command( unsigned char cmnd )
{
	lcd_port = (cmnd & 0xF0); /* sending upper nibble */
	lcd_port &= ~ (1<<RS);				/* RS=0, command reg. */
	PORTB |= (1<<EN);				/* Enable pulse */
	_delay_us(1);
	lcd_port &= ~ (1<<EN);
	lcd_port = (cmnd << 4);  /* sending lower nibble */
	lcd_port |= (1<<EN);
	_delay_us(1);
	lcd_port &= ~ (1<<EN);
	_delay_ms(2);
}


void lcd_sending_data( unsigned char data )
{
	lcd_port =  (data & 0xF0); /* sending upper nibble */
	lcd_port |= (1<<RS);				/* RS=1, data reg. */
	lcd_port |= (1<<EN);
	_delay_us(1);
	lcd_port &= ~ (1<<EN);
	lcd_port = (data << 4); /* sending lower nibble */
	lcd_port |= (1<<RS);
	lcd_port |= (1<<EN);
	_delay_us(1);
	lcd_port &= ~ (1<<EN);
	_delay_ms(2);
}


void lcd_initialization (void)					/* LCD Initialize function */
{
	lcd_ddr = 0xFF;						/* Make LCD command port direction as o/p */
	_delay_ms(20);						/* LCD Power ON delay always >15ms */
	lcd_sending_command(0x33);			/* Ensures display is in 8-bit mode */
	lcd_sending_command(0x32);		    /* send for 4 bit initialization of LCD  */
	lcd_sending_command(0x28);          /* Use 2 line and initialize 5*7 matrix in (4-bit mode)*/
	lcd_sending_command(0x0f);          /* Display on, cursor on and blink cursor*/
	lcd_sending_command(0x01);          /* Clear display screen*/
	lcd_sending_command(0x06);          /* Clear display screen*/
	lcd_sending_command(0x02);          /* Clear display screen*/
	_delay_ms(2);

}


void lcd_display_string (char *str)				/* Send string to LCD function */
{
	int i;
	for(i=0;str[i]!=0;i++)				/* Send each char of string till the NULL */
	{
		lcd_sending_data (str[i]);
	}
}

void lcd_string_float(float LCD_number, int LCD_line, int LCD_cursor_position)
{
	char buffer_LCD[13];

	dtostre(LCD_number, buffer_LCD, 5, 4);
	lcd_display_string(buffer_LCD);
}

int main()
{
	char Voltage[10];
	ADC_Init();                 /* initialize ADC*/
	int i;
	lcd_initialization();							/* Initialization of LCD*/
	lcd_display_string("DC Voltage");
	lcd_sending_command(0xc0);                  /* Go to 2nd line*/
  while	(1) {
		volt = (float)ADC_Read(3)*3.3/1024;
		// volt = (volt/10.00);
		lcd_sending_command(0xc0);
        lcd_sending_command(0x0C);
		lcd_string_float(volt,2,1 );/* send string data for printing */
		lcd_display_string(" V"); 
        _delay_ms(10); 
	}

}