Colony » Colony Scout

/*

* cliffSensor.cpp

*

* Created: 2012-9-24 17:38:59

*  Author: Anson

*/

#include "cliffSensor.h"

#include <avr/io.h>

#include <avr/interrupt.h>

unsigned char flag_cliff0=0,flag_cliff1=0,flag_cliff2=0; // are these global variables???

void cliffSensor_init(void)

{

  sei();   //set the I-bit of SREG to 1, enabling global interrupters

        EIMSK |= 0b01000011; //enable INT0,INT1,INT6

        EICRA |= 0b00001111; 

        EICRB |= 0b00110000; //The rising edge of INTn triggers an interrupt request.

  DDRD &= ~(0b00000011);

  DDRE &= ~(0b01000000); // set PD0, PD1 and PE6 as input pins.

}

bool read_cliffSensor_front(void)

{

        if(flag_cliff0 || (PIND & (1<<PD0))) //either a rising edge or a high logic level will be determined as cliff

        {

                flag_cliff0 = 0; // reset the flag

                EIMSK |= (1<<INT0); // re-enable the interrupt

                return true;

        }

        return false;

}

bool read_cliffSensor_left(void)

{

        if(flag_cliff1 || (PIND & (1<<PD1)))

        {

                flag_cliff1 = 0;

                EIMSK |= (1<<INT1);

                return true;

        }

        return false;

}

bool read_cliffSensor_right(void)

{

        if(flag_cliff2 || (PINE & (1<<PE6)))

        {

                flag_cliff2 = 0;

                EIMSK |= (1<<INT6); // enable INT6

                return true;

        }

        return false;

}

unsigned char read_cliffSensor_all(void) // return a 3-digit binary number(left, front, right)

{

        unsigned char result=0;

        if(read_cliffSensor_left()){result |= 0b100;}

        if(read_cliffSensor_front()){result |= 0b010;}

        if(read_cliffSensor_right()){result |= 0b001;}

        return result;

}

ISR(INT0_vect)

{

        flag_cliff0 = 1;

        EIMSK &= ~(1<<INT0); // disable INT0

}

ISR(INT1_vect){

        flag_cliff1 = 1;

        EIMSK &= ~(1<<INT1); // disable INT1

}

ISR(INT6_vect){

        flag_cliff2 = 1;

        EIMSK &= ~(1<<INT6); // disable INT6

}