109 lines
2.0 KiB
C
109 lines
2.0 KiB
C
/*
|
|
* ultrasonicSensor.c
|
|
*
|
|
* Created: 17-3-2021 09:47:12
|
|
* Author : Sem
|
|
|
|
interrupt op rising edge in echo,
|
|
dan timer1 aanzetten -> timer1 want 16 bits en willen nauwkeurig afstand kunnen meten, en afstand kan van 2 cm tot 4 m, dus willen zeker zijn dat het past
|
|
en interrupt zetten op falling edge in echo
|
|
als falling edge interrupt geeft ->
|
|
waarde uit timer1 uitlezen
|
|
en formule gebruiken high level time * velocity (340M/S) / 2
|
|
timer1 uitzetten
|
|
interrupt weer op rising edge van echo zetten
|
|
|
|
|
|
|
|
*/
|
|
#define F_CPU 20e6
|
|
|
|
#include <avr/io.h>
|
|
#include <util/delay.h>
|
|
#include <avr/interrupt.h>
|
|
|
|
#include "lcd_control.h"
|
|
|
|
enum interrupt_status {INTERRUPT_FALLING, INTERRUPT_RISING};
|
|
|
|
static enum interrupt_status int_stat = INTERRUPT_RISING;
|
|
|
|
void wait_us(unsigned int us)
|
|
{
|
|
for(int i = 0; i < us; i++)
|
|
{
|
|
_delay_us(1);
|
|
}
|
|
}
|
|
|
|
void wait_ms(unsigned int ms)
|
|
{
|
|
|
|
for(int i = 0; i < ms; i++)
|
|
{
|
|
_delay_ms(1);
|
|
}
|
|
}
|
|
|
|
void ultrasonic_send_pulse()
|
|
{
|
|
PORTG = 0x00; // 10 us low pulse
|
|
wait_us(10);
|
|
PORTG = 0x01;
|
|
}
|
|
|
|
ISR(INT0_vect)
|
|
{
|
|
|
|
// if the interrupt was generated on a rising edge (start sending echo)
|
|
if (int_stat == INTERRUPT_RISING)
|
|
{
|
|
// set interrupt pin 0 on PORTD to falling edge
|
|
EICRA = 0x02;
|
|
|
|
// set interrupt status
|
|
int_stat = INTERRUPT_FALLING;
|
|
} else
|
|
// else if it was generated on a falling edge (end sending echo)
|
|
{
|
|
// set interrupt pin 0 on PORTD to rising edge
|
|
EICRA = 0x03;
|
|
|
|
// set interrupt status
|
|
int_stat = INTERRUPT_RISING;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
int main(void)
|
|
{
|
|
DDRG = 0xFF; // port g all output. pin 0 is trig, the rest is for debug
|
|
DDRD = 0x00; // port D pin 0 on input. 0 is echo and also interrupt
|
|
|
|
DDRA = 0xFF;
|
|
|
|
EICRA |= 0x03; // interrupt PORTD on pin 0, rising edge
|
|
|
|
EIMSK |= 0x01; // enable interrupt on pin 0 (INT0)
|
|
|
|
sei(); // turn on interrupt system
|
|
|
|
/* Replace with your application code */
|
|
while (1)
|
|
{
|
|
ultrasonic_send_pulse();
|
|
if (int_stat == INTERRUPT_FALLING)
|
|
{
|
|
PORTA = 0xFF;
|
|
} else {
|
|
PORTA = 0x00;
|
|
}
|
|
|
|
wait_ms(100);
|
|
}
|
|
}
|
|
|
|
|
|
|