#include "p1.h"

#include "flex_lcd.c"

/////////////*FUNCTION DECLARATIONS*///////////////

void init_pic(); //

void setTimer(); //

int checkTimer(); //

void rayCrossed_isr(); //

void clock_isr(); //

int32 convertToCelsius(); //

int convertToASCII(int16 number); //

void lcd_display(int16 number, int x, int y); //

void initialDisplay(); //

int16 read_temperature(); //

void lcd_display_temperature(); //

void phaseControl(); //

///////////////////////////////////////////////////

/////////////////*GLOBAL VARIABLES*/////////////////////////////////////////////////

int16 noOfPeople = 3; // Number of people inside the room //

int int_count; // Number of interrupts left before a second has elapsed //

int unitsPosition, tensPosition, hundredsPosition; //

//

int1 rayOne = 0; // to record when first beam get crossed //

int1 rayTwo = 0; // to record when second beam get crossed //

int1 pin_changed = 1; //

int1 number_changed = 1; //

//

int16 mseconds =0; //

int16 counter_for_temp=0 ; //

//

int16 temperature=27; //

//

int16 t; // The A/D conversion of the analog input //

// signal results in a corresponding 10-bit digital number. //

// this variable is to store that //

////////////////////////////////////////////////////////////////////////////////////

void main()

{

init_pic();

initialDisplay();

/* only if the number of people changes the value shown in lcd is changed.

And temperature is updated when counter_for_temp overflows.*/

while(1)

{

phaseControl();

if(number_changed)

{

lcd_display(noOfPeople,14,1);

number_changed = 0;

}

if(counter_for_temp == 65535)

{

lcd_display_temperature();

counter_for_temp=0;

}

counter_for_temp++;

}

}

/* when timer0 counter overflows(0-255) an interrup occurs. int count which is initially

* set to INTS_PER_mS, is decremented by 1 inside the isr.

* When int_count reaches 0, no of miliseconds is incremented by 1

*/

#int_RTCC

void clock_isr() {

if(--int_count==0)

{

++mseconds;

int_count=INTS_PER_mS;

}

}

//Whenever a beam get crossed this isr is invoked.

#int_EXT

void rayCrossed_isr()

{

if(INPUT(PIN_B2))

{

rayTwo = 1;

if(checkTimer() == 2 && rayOne == 1)

{

rayOne = 0;

}

if(rayOne == 1)

{

if(checkTimer() == 1)

{

noOfPeople++ ;

number_changed = 1;

}

rayOne = 0;

rayTwo = 0;

}

setTimer();

}

else if(INPUT(PIN_B1))

{

rayOne = 1;

if(checkTimer() == 2 && rayTwo == 1)

{

rayTwo = 0;

}

if(rayTwo == 1)

{

if(checkTimer() == 1 && noOfPeople>0)

{

noOfPeople-- ;

number_changed = 1;

}

rayOne = 0;

rayTwo = 0;

}

setTimer();

}

}

void setTimer()

{

int_count=INTS_PER_mS;

set_timer0(0);

mseconds=0;

}

/* When both rayOne =1 and rayTwo = 1, this is called */

int checkTimer()

{

if((mseconds <= MAX_CROSSING_TIME) && (mseconds >= MIN_CROSSING_TIME))

{

return 1;

}

else if(mseconds > MAX_CROSSING_TIME)

{

return 2;

}

else

{

return 0;

}

}

int32 convertToCelsius()

{

return (t*150)/307;

}

void lcd_display_temperature()

{

temperature =read_temperature();

lcd_display(temperature,13,2);

}

int convertToASCII(int16 number)

{

return (number+48);

}

void lcd_display(int16 number, int x, int y)

{

int unitsPosition, tensPosition, hundredsPosition;

unitsPosition =number % 10;

tensPosition = ((number - (number % 10))%100)/10;

hundredsPosition = ((number - (number%100))%1000)/100;

lcd_gotoxy(x,y);

lcd_putc(convertToASCII(hundredsPosition));

lcd_putc(convertToASCII(tensPosition));

lcd_putc(convertToASCII(unitsPosition));

}

int16 read_temperature()

{

delay_us(12); //a small delay is required after setting the channel

t = read_adc();

return convertToCelsius();

}

void initialDisplay()

{

delay_ms(25);

lcd_init();

lcd_gotoxy(1,1);

lcd_putc("SYSTEM STARTED..");

lcd_gotoxy(1,2);

lcd_putc("================");

delay_ms(500);

lcd_gotoxy(1,1);

lcd_putc("\fNumberInside:");

lcd_display(noOfPeople,14,1);

lcd_gotoxy(1,2);

lcd_putc("Temperature: C");

}

void init_pic()

{

setup_adc_ports(AN0);

setup_adc(ADC_CLOCK_DIV_32);

setup_psp(PSP_DISABLED);

setup_spi(FALSE);

setup_counters( RTCC_INTERNAL, RTCC_DIV_1 | RTCC_8_BIT);

setup_timer_1(T1_DISABLED);

setup_timer_2(T2_DISABLED,0,1);

setup_comparator(NC_NC_NC_NC);

setup_vref(FALSE);

enable_interrupts(INT_RTCC);

enable_interrupts(INT_EXT);

enable_interrupts(GLOBAL);

EXT_INT_EDGE(L_TO_H);

OUTPUT_B(0);

OUTPUT_C(0);

SET_TRIS_B(0b01000111); //pins B0, B1, B2 and B6 are set to give inputs. B0 is the external interuupt pin

//B0, B1 & B2 are used for people counting. B6 for zero crossing detection in fan controlling

SET_TRIS_C(0b00000000);

SET_TRIS_D(0b00000000); //D port except D0 pin, is used for lcd panel

set_adc_channel(0); //the next read_adc call will read channel 0

}

/*

the fan is controlled using phase control method.

Fan is on only if the number of people >0

*/

void phaseControl()

{

switch(noOfPeople)

{

case 0: OUTPUT_HIGH(PIN_B7);

break;

default:

if(INPUT(PIN_B6) && pin_changed == 1)

{

if(0<=temperature && temperature<20)

{

OUTPUT_HIGH(PIN_B7);

}

else if(temperature>=20&& temperature<23)

{

delay_us(6000);

OUTPUT_LOW(PIN_B7);

delay_us(500);

OUTPUT_HIGH(PIN_B7);

}

else if(temperature>=23 && temperature<25)

{

delay_us(5000);

OUTPUT_LOW(PIN_B7);

delay_us(500);

OUTPUT_HIGH(PIN_B7);

}

else if(temperature>=25 && temperature<27)

{

delay_us(4500);

OUTPUT_LOW(PIN_B7);

delay_us(500);

OUTPUT_HIGH(PIN_B7);

}

else if(temperature>=27 && temperature<30)

{

delay_us(4000);

OUTPUT_LOW(PIN_B7);

delay_us(500);

OUTPUT_HIGH(PIN_B7);

}

else if(temperature>=30)

{

OUTPUT_LOW(PIN_B7);

}

pin_changed = 0;

}

if(!INPUT(PIN_B6))

{

pin_changed = 1;

}

}

}