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

                                                            AVR LIVE BATCH-8

1.

AIM:

To implement the code for “Measuring distance of an object using ultrasonic distance sensor (HC-SR04)

OBJICTIVE:

• To Measuring distance of an object using ultrasonic distance sensor (HC-SR04)
• Usage of Input Capture Mode

PROGRAM:-

#include 
#define F_CPU 8000000UL//CPU frequency
#include 
#include //for delay function
#include //for string
#include 
#define LCD_Data_Dir DDRD //LCD data port direction
#define LCD_Command_Dir DDRC //LCD command port direction register
#define LCD_Data_Port PORTD //LCD data port
#define LCD_Command_Port PORTC //LCD data port
#define EN PC2 //Enable signal pin
#define RW PC3 //Read/Write signal pin
#define RS PC4 // Define Register Select
void LCD_Command (char); // LCD command write function
void LCD_Char (char); // LCD data write function
void LCD_Init (void); // LCD Initialize function
void LCD_String (char*); // Send string to LCD function
void LCD_String_xy (char,char,char*); // Send row, position and string to LCD function
void LCD_Command (char cmd) // LCD command write function
{
LCD_Data_Port = cmd; // Write command data to LCD data port
LCD_Command_Port &= ~((1<15ms
LCD_Command (0x38); // Initialize 16X2 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 function
{
int i;
for(i=0;str[i]!=0;i++) //Send each char of string till the NULL
{
LCD_Char (str[i]); // Call LCD data write
}
}
void LCD_String_xy (char row, char pos, char *str) // Send string to LCD function
{
if (row == 1)
LCD_Command((pos & 0x0F)|0x80); // Command of first row and required position<16
else if (row == 2)
LCD_Command((pos & 0x0F)|0xC0); // Command of Second row and required position<16
LCD_String(str); // Call LCD string function
}
#define Trigger_pin PA0 // Trigger pin
int TimerOverflow = 0;
ISR(TIMER1_OVF_vect)
{
TimerOverflow++; // Increment Timer Overflow count
}
int main(void)
{
char string[10];
long count;
double distance;
DDRA = 0x01; // Make trigger pin as output
PORTB = 0xFF; // Turn on Pull-up
LCD_Init();
LCD_String_xy(1, 0, "Ultrasonic");
sei(); // Enable global interrupt
TIMSK = (1 << TOIE1); //Timer1 overflow interrupts
TCCR1A = 0; // Set all bit to zero
while(1)
{
// Give 10us trigger pulse on trig. pin to HC-SR04
PORTA |= (1 << Trigger_pin);
_delay_us(10);
PORTA &= (~(1 << Trigger_pin));
TCNT1 = 0; // Clear Timer counter
TCCR1B = 0x41; // Capture on rising edge, No prescaler
TIFR = 1<