Project 2 - Measuring distance of an object using ultrasonic sensor (HC-SR04)
CODE:
/*
* Distance_Measuring.c
*
* Created: 12/4/2023 8:57:33 AM
* Author : SATYAKI
*/
#define F_CPU 8000000UL
#include
#include
#include
#include
#include
#define LCD_Data_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 LCD data port */
#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 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< LCD_Command_Port |= (1< _delay_us(1); LCD_Command_Port &= ~(1< _delay_ms(3); /* Wait little bit */ } void LCD_Char (char char_data) /* LCD data write function */ { LCD_Data_Port = char_data; /* Write data to LCD data port */ LCD_Command_Port &= ~(1< LCD_Command_Port |= (1< _delay_us(1); LCD_Command_Port &= ~(1< _delay_ms(1); /* Wait little bit */ } void LCD_Init (void) /* LCD Initialize function */ { LCD_Command_Dir |= (1< LCD_Data_Dir = 0xFF; /* Make LCD data port direction as o/p */ _delay_ms(20); /* LCD power up time to get things ready, it should always >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); /* Enable Timer1 overflow interrupts */ TCCR1A = 0; /* Set all bit to zero Normal operation */ 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< TIFR = 1< /*Calculate width of Echo by Input Capture (ICP) */ while ((TIFR & (1 << ICF1)) == 0);/* Wait for rising edge */ TCNT1 = 0; /* Clear Timer counter */ TCCR1B = 0x01; /* Capture on falling edge, No prescaler */ TIFR = 1< TIFR = 1< TimerOverflow = 0; /* Clear Timer overflow count */ while ((TIFR & (1 << ICF1)) == 0); /* Wait for falling edge */ count = ICR1 + (65535 * TimerOverflow); /* Take count */ /* 8MHz Timer freq, sound speed =343 m/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); } } OUTPUT:
