Project 2 - Measuring distance of an object using ultrasonic sensor (HC-SR04)

ABINAYA INBAMANI MAM (LIVE BATCH)

PROJECT 2

#include <avr/io.h>
#define F_CPU 8000000UL
#include <util/delay.h>
#include <string.h>
#include <stdlib.h>

#define LCD_Date_Dir DDRD //define LCD data port direction
#define LCD_Command_Dir DDRC //Define LCD command port direction register
#define LCD_Data_Port PORTD //Define LCD data port
#define LCD_Command_Port PORTC //
#define EN PC2 // define Enable signal pin
#define RW PC3 //Define read/write signal pin
#define RS PC4 //define register select (data reg./command reg.) signal pin

void LCD_Command(char); //lcd command write funtion
void LCD_Char(char); //lcd data write function
void LCD_Init(void); //lcd initialize function
void LCD_String(char*); //send string to lcd funtion
void LCD_String_xy(char,char,char*); //send row position and string to lcd funtion

void LCD_Command (char cmd) // lcd command write funtion
{
LCD_Data_Port=cmd; // write command daata to lcd data port..
LCD_Command_Port&=~((1<<RS)|(1<<RW)); //RS low (command reg.) RW low (write)
LCD_Command_Port|=(1<<EN); // high to low transition on EN
_delay_ms(1);
LCD_Command_Port&=~(1<<EN);
_delay_ms(2); // wait little bit

}

void LCD_Char(char char_data) //LCD data write function
{
LCD_Data_Port = char_data; //write data to lce data port
LCD_Command_Port &=~(1<<RW); //RW low (write)
LCD_Command_Port |=((1<<EN)|(1<<RS)); //RS high (data reg). high to low transis=tion on EN
_delay_ms(1);
LCD_Command_Port &=~(1<<EN);
_delay_ms(1); //wait little bit
}

void LCD_Init(void)
{
LCD_Command_Dir|=(1<<RS)|(1<<RW)|(1<<EN); //LCD COmmand port direction as o/p
LCD_Date_Dir =0xFF; //lcd data port direction as o/p

_delay_ms(20); // lcd power up time to get things ready its always >15ms
LCD_Command(0x38); //initialize 16*2 lcd in 8bit mode
LCD_Command(0x0C);//display on, cursor off command
LCD_Command(0x06);//auto increment cursor
LCD_Command(0x01);//clear lcd command
LCD_Command(0x80); //8 is for first line and 0 is for 0th position
}
void LCD_String(char *str) // send string to lcd fun
{
int i;
for (i=0;str[i]!=0;i++) //send each char of string til null
{
LCD_Char(str[i]);
}
}
void LCD_String_xy(char row,char pos,char *str)
{
if(row==1)
LCD_Command((pos & 0x0F)|0x80); // command of 1st row and required position<16
else if (row==2)
LCD_Command((pos &0X0F)|0XC0); // 2ND ROW AND REQUIRED POSITION<16
LCD_String(str); //LCD string fun
}
#define Tigger_pin PA0 // trigger pin
int timeroverflow =0;
ISR (TIMER1_OVF_vect)
{
timeroverflow++; // TIMER OVERFLOW COUNT
}
int main(void)
{
char string[10];
long count;
double distance;

DDRA = 0X01; //trigger pin as output
PORTB =0xFF; // turn on pull up
LCD_Init();
LCD_String_xy(1,0,"ultrasonic");

//sei(); // global interrupt
TIMSK =(1<<TOIE1);// ENABLEE TIMER1 OVERFLOW INTERRUPTS
TCCR1A = 0; // SET ALL BIT TO ZERO NORMAL OPERATION

while (1)
{
PORTA |=(1<< Tigger_pin);
_delay_ms(10);
PORTA &=(~(1<<Tigger_pin));

TCNT1=0; //clear timer counter
TCCR1B =0x41; //rising edge, no prescaler
TIFR = 1<<ICF1; //clear icp flag //input capture flag
TIFR = 1<<TOV1; //clear timer overflow flag

while ((TIFR &(1<<ICF1)) == 0); // wait for rising edge
TCNT1=0; //clear timer counter
TCCR1B=0x01;//on falling edge,no prescaler
TIFR=1<<ICF1; //clear icp flag (i/p capture flag
TIFR=1<<TOV1;// clear timer overfloer flag
timeroverflow =0; // clear timer overflow count

while((TIFR &(1<<ICF1))==0); // Wait for fallling edge
count = ICR1+(65535*timeroverflow); // take count
// 8MHZ timer freq, sound speed=343m/s
distance = (double) count/466.47;

dtostrf(distance,2,2,string); //distance to string
strcat (string,"cm"); //concat unit i e. cm
LCD_String_xy(2,0,"Dist= ");
LCD_String_xy(2,7,string); //print distance
_delay_ms(200);

}
}

code succed

output