How can i add a cooler in my pic16f877a microcontroller. My program is in C.

[HerohetoChakma]

I need to add a cooler with my program. My Program is in c. I need to on cooler when temperature will exist my set point and it will also stop when temperature will below the set point. My program is given bellow. Could anybody help me please????
#include <16f877a.h>
#include <math.h>
#include "config.h"
//===============configuration==============================
__CONFIG (0x3F32);
//===============define IO port=============================
#define lcd PORTD
#define RS RB4
#define E RB5
#define led1 RB6
#define redled RB7
#define CHANNEL0 0b10000001
#define CHANNEL1 0b10001001
#define buzzer RB2
#define orangeled RB3
#define greenled RB0
//==============FUNCTION PTOTOTYPE=========================
void e_pulse(void);
void delay(unsigned short i);
void send_char(unsigned char data);
void send_string(const char *s);
void send_config(unsigned char data);
void lcd_goto(unsigned char data);
void lcd_clr(void);
void dis_num(unsigned long data);
void increment(unsigned long data);
void read_adc(void);
unsigned short read_temp(void);
void blink_LED1(unsigned char n);
void blink_redled(unsigned char n);
void blink_orangeled(unsigned char n);
void clearrow1(void);
void clearrow2(void);
void clearrow3(void);
void clearrow4(void);
void scancolumn1(void);
void scancolumn2(void);
void scancolumn3(void);
void scancolumn4(void);
void beep_once(void);
//====================MAIN================================
unsigned short result;
unsigned short temp;
float tempB,tempA;
unsigned char keyin[3];
unsigned char num_count=0;
void main(void)
{
ADRESH=0;
ADRESL=0;

ADCON1=0b11000000;
TRISA=0b11111111;
TRISB=0b00000000;
TRISC=0b00001111;
TRISD=0b00000000;
TRISE=0b00000000;
PORTA=0;
PORTB=0;

CCP1CON==0b00001100;
PR2=0xFF;
T2CON=0b00000101;
CCPR1L=0;

send_config(0b00000001);
send_config(0b00000010);
send_config(0b00000110);
send_config(0b00001100);
send_config(0b00111000);
lcd_clr();
delay(1000);
lcd_goto(0);
send_string("PLEASE ENTER");
lcd_goto(20);
send_string("2 DIGIT SPEC");
while(1)
{
clearrow1();
scancolumn1();
clearrow2();
scancolumn2();
clearrow3();
scancolumn3();
clearrow4();
scancolumn4();
if(num_count==2)
{
delay(8000);
lcd_goto(0);
//display character on LCD
send_char(' ');
send_char('S');
send_char('P');
send_char('E');
send_char('C');
send_char('.');
send_char('.');
send_char('=');
lcd_goto(20);
//display character on LCD
send_char(' ');
send_char('M');
send_char('E');
send_char('A');
send_char('S');
send_char('U');
send_char('R');
send_char('E');
send_char('D');
send_char('=');
while(1)
{
//keypad value
ADCON0=CHANNEL1;
lcd_goto(9);
keyin[2]=0;
tempA=(keyin[0]-0x30)*10+(keyin[1]-0x30);
dis_num((unsigned long)round(tempA));
send_char(0b11011111);
send_char('C');
send_char(' ');
send_char(' ');
//sensor B the LM35 sensor
ADCON0=CHANNEL0;
lcd_goto(31);
read_adc();
temp=read_temp();
tempB=(((float)temp)*0.48876);
dis_num((unsigned long)round(tempB));
send_char(0b11011111);
send_char('C');
send_char(' ');
send_char(' ');
if(tempB<tempA)
{
if((tempB+5)>=tempA)
{
led1=1;
blink_LED1(10);
greenled=1;
orangeled=1;
blink_orangeled(3);
redled=0;
buzzer=0;
}
else
{
led1=1;
blink_LED1(10);
greenled=1;
orangeled=0;
redled=0;
buzzer=0;
}
}
else if(tempB>tempA)
{
led1=1;

blink_LED1(3);
greenled=0;
orangeled=1;
blink_orangeled(3);
redled=1;

blink_redled(3);
buzzer=1;
beep_once();
}
delay(2000);
}
}
}
}
//=============================================================================
// Keypad scanning functions
//=============================================================================
void clearrow1(void)
{
RC7=0;
RC6=1;
RC5=1;
RC4=1;
}
void clearrow2(void)
{
RC7=1;
RC6=0;
RC5=1;
RC4=1;
}
void clearrow3(void)
{
RC7=1;
RC6=1;
RC5=0;
RC4=1;
}
void clearrow4(void)
{
RC7=1;
RC6=1;
RC5=1;
RC4=0;
}
void scancolumn1(void)
{
if(RC0==0)
{
while(RC0==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('1');
keyin[num_count]='1';
num_count+=1;
}
else if(RC1==0)
{
while(RC1==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('2');
keyin[num_count]='2';
num_count+=1;
}
else if(RC2==0)
{
while(RC2==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('3');
keyin[num_count]='3';
num_count+=1;
}
}
void scancolumn2(void)
{
if(RC0==0)
{
while(RC0==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('4');
keyin[num_count]='4';
num_count+=1;
}
else if(RC1==0)
{
while(RC1==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('5');
keyin[num_count]='5';
num_count+=1;
}
else if(RC2==0)
{
while(RC2==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('6');
keyin[num_count]='6';
num_count+=1;
}
}
void scancolumn3(void)
{
if(RC0==0)
{
while(RC0==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('7');
keyin[num_count]='7';
num_count+=1;
}
else if(RC1==0)
{
while(RC1==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('8');
keyin[num_count]='8';
num_count+=1;
}
else if(RC2==0)
{
while(RC2==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('9');
keyin[num_count]='9';
num_count+=1;
}
}
void scancolumn4(void)
{
if(RC0==0)
{
while(RC0==0)continue;
if(num_count==0)lcd_clr();
cd_goto(num_count);
send_char('*');
keyin[num_count]='*';
num_count+=1;
}
else if(RC1==0)
{
while(RC1==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('0');
keyin[num_count]='0';
num_count+=1;
}
else if(RC2==0)
{
while(RC2==0)continue;
if(num_count==0)lcd_clr();
lcd_goto(num_count);
send_char('#');
keyin[num_count]='#';
num_count+=1;
}
}
//==================subroutine LCD setting ==========================
void send_config(unsigned char data)
{
RS=0;
lcd=data;
delay(500);
e_pulse();
}
void e_pulse(void)
{
E=1;
delay(500);
E=0;
delay(500);
}
void send_char(unsigned char data)
{
RS=1;
lcd=data;
delay(500);
e_pulse();
}
void lcd_goto(unsigned char data)
{
if(data<16)
{
send_config(0x80+data);
}
else
{
data=data-20;
send_config(0xc0+data);
}
}
void lcd_clr(void)
{
RS=0;
send_config(0x01);
delay(600);
}
void send_string(const char *s)
{
unsigned char i=0;
while (s && *s)send_char (*s++);
}
void dis_num(unsigned long data)
{
unsigned char hundred_thousand;
unsigned char ten_thousand;
unsigned char thousand;
unsigned char hundred;
unsigned char tenth;
hundred_thousand = data/100000;
data = data % 100000;
ten_thousand = data/10000;
data = data % 10000;
thousand = data / 1000;
data = data % 1000;
hundred = data / 100;
data = data % 100;
tenth = data / 10;
data = data % 10;
if(hundred_thousand>0)
{
send_char(hundred_thousand + 0x30);
send_char(ten_thousand + 0x30);
send_char(thousand + 0x30);
send_char(hundred + 0x30);
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(ten_thousand>0)
{
send_char(ten_thousand + 0x30);
send_char(thousand + 0x30);
send_char(hundred + 0x30);
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(thousand>0)
{
send_char(thousand + 0x30);
send_char(hundred + 0x30);
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(hundred>0)
{
send_char(hundred + 0x30);
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(tenth>0)
{
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else send_char(data + 0x30);
}
void increment(unsigned long data)
{
unsigned short j;
for(j=10;j>0;j--)
{ lcd_goto(32);
data=data+1;
dis_num(data);
delay(10000);
}
}
//==================subroutine ADC=========================
void read_adc(void)
{
unsigned short i;
unsigned long result_temp=0;
for(i=2000;i>0;i-=1)
{
ADGO = 1;
while(ADGO==1);
result=ADRESH;
result=result<<8;
result=result|ADRESL;
result_temp+=result;
}
result = result_temp/2000;
}
unsigned short read_temp(void)
{
unsigned short temp;
temp=result;
return temp;
}
//==================subroutine DELAY==========================
void delay(unsigned short i)
{
for(;i>0;i--);
}
//==================led blinking============================
void blink_LED1(unsigned char n)
{
//loop for n times
for(n+=1;n>0;n-=1)
{
//set LED1 to 1
led1=1;
//short delay
for(unsigned int i=0;i<20000;i+=1);
//set LED1 to 1
led1=0;
//short delay
for(unsigned int i=0;i<20000;i+=1);
}
}
//function to blink redled for n times
void blink_redled(unsigned char n)
{
//loop for n times
for(n+=1;n>0;n-=1)
{
//set redled to 1
redled=1;
//short delay
for(unsigned int i=0;i<20000;i+=1);
//set redled to 1
redled=0;
//short delay
for(unsigned int i=0;i<20000;i+=1);
}
}
//function to blink redled for n times
void blink_orangeled(unsigned char n)
{
//loop for n times
for(n+=1;n>0;n-=1)
{
//set redled to 1
orangeled=1;
//short delay
for(unsigned int i=0;i<20000;i+=1);
//set redled to 1
orangeled=0;
//short delay
for(unsigned int i=0;i<20000;i+=1);
}
}
//==================Buzzer Beeping============================
void beep_once(void)
{
buzzer=1;
delay(10);
buzzer=0;
delay(20);
buzzer=1;
delay(10);
buzzer=0;
}

In this program LED and Buzzer will beep when temperature will exist my set point but i want also a cooler to add with this program.

 

[Electro nS]

you should connect the tempreture sensor to your board .

read the value of the analog output , then comapre that the the setpoint value . if more , digital output high to the pin connected to the transistor operating the fan


but make sure to make it hysteresis.
which means for example : if (temp>70)
{ fanpin = true;}
if (temp<40)
{ fanpin = false:}
so the fan will run when tempreture is over a high level , but will continue to run , even if the temp goes under this value . and finally it will turn of when temp is lower than low level. otherwise , the fan will keep turning on and off causing problems .

hope that helps