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Lm35 interface with PIC16f877

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jeremy1409

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Hi everyone, i would like to find some help here.i m doing temperature control system by using LM35, and i do copy the coding from Cyctron company and the product code is PR11. But the PIC they using is 16f876, and the coding is to control two temperature sensor. My project just need one temperature sensor and display display only one reading but i got no idea how to modify the code to fix my project. Need help here.thx~~~and the coding i m writing is using C programing.

This is coding i copy from Cyctron.

//==========================================================================
// Author : Cytron Technologies
// Project : Temperature Control System using LM35
// Project description : This project will use PIC16F876A to control NPN power transistor (BD135)
// further drive DC brushless fans, LEDs and buzzer when the certain
// temperature was detected.
//==========================================================================
//==================inckude=================================
#include<pic.h>

//===============configuration==============================
__CONFIG (0x3F32);

//===============define IO port=============================
#define lcd PORTC
#define RS RA2
#define E RA5
#define CHANNEL0 0b10000001 // AN0
#define CHANNEL1 0b10001001 // AN1
#define buzzer RB5
#define fanA RB4
#define fanB RB3
#define ledA RB2
#define ledB RB1

//==============FUNCTION PTOTOTYPE=========================
void e_pulse(void);
void delay(unsigned short i);
void send_char(unsigned char data);
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);

//====================MAIN================================
unsigned short result;
unsigned short temp,tempA,tempB;

void main(void)
{
ADRESH=0; //clear A/D result
ADRESL=0; //clear A/D result

//setting ADCON1 Register
ADCON1=0b11000101; // A/D result right justified,
// configure RA2 and RA5 as digital I/O

TRISA=0b11011011; //configure PORTA I/O direction
TRISB=0b00000000; //configure PORTB as output
TRISC=0b00000000; //configure PORTC as output

PORTA=0;
PORTB=0;

while(1)
{
send_config(0b00000001); //clear display at lcd
send_config(0b00000010); //Lcd Return to home
send_config(0b00000110); //entry mode-cursor increase 1
send_config(0b00001100); //diplay on, cursor off and cursor blink off
send_config(0b00111000); //function set

lcd_goto(0); //cursor start from beginning

//display character on LCD
send_char(' ');
send_char('T');
send_char('E');
send_char('M');
send_char('P');
send_char('.');
send_char('A');
send_char('=');

lcd_goto(20); //cursor go to 2nd line of the LCD

//display character on LCD
send_char(' ');
send_char('T');
send_char('E');
send_char('M');
send_char('P');
send_char('.');
send_char('B');
send_char('=');

while(1) //infinity loop
{
//sensor A
ADCON0=CHANNEL0; //CHANNEL1=0b10001001
lcd_goto(8);

read_adc();

temp=read_temp();
dis_num(temp/10);
send_char('.');
dis_num(temp%10);
send_char(0b11011111);
send_char('C');
send_char(' ');
send_char(' ');

tempA=temp;

//sensor B
ADCON0=CHANNEL1; //CHANNEL0=0b10000001

lcd_goto(28);

read_adc();

temp=read_temp();
dis_num(temp/10);
send_char('.');
dis_num(temp%10);
send_char(0b11011111);
send_char('C');
send_char(' ');
send_char(' ');

tempB=temp;

if((tempA>400)&&(tempB<350)) // *****************************************
{ // * LED A and Fan A activated only for *
ledA=1; // * temperature A greater than 40'C *
ledB=0; // * and temperature B less than 35'C *
fanA=1; // *****************************************
fanB=0;
buzzer=0;
}

else if((tempB>350)&&(tempA<400)) // *****************************************
{ // * LED B and Fan B activated only for *
ledA=0; // * temperature A less than 40'C and *
ledB=1; // * temperature B greater than 35'C *
fanA=0; // *****************************************
fanB=1;
buzzer=0;
}

else if((tempB>350)&&(tempA>400)) // *****************************************************
{ // * All LED A & LED B, Fan A & Fan B and Buzzer *
ledB=1; // * activated for temperature A greater than 40'C *
ledA=1; // * and temperature B greater than 35'C *
fanA=1; // *****************************************************
fanB=1;
buzzer=1;
}

else if((tempB<350)&&(tempA<400)) // *****************************************************
{ // * All LED A & LED B, Fan A & Fan B and Buzzer *
ledB=0; // * disactivated for temperature A less than 40'C *
ledA=0; // * and temperature B less than 35'C *
fanA=0; // *****************************************************
fanB=0;
buzzer=0;
}

delay(2000);

}

}

}



//==================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 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); //0x30 added to become ASCII code
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); //0x30 added to become ASCII code
send_char(thousand + 0x30);
send_char(hundred + 0x30);
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(thousand>0)
{
send_char(thousand + 0x30); //0x30 added to become ASCII code
send_char(hundred + 0x30);
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(hundred>0)
{
send_char(hundred + 0x30); //0x30 added to become ASCII code
send_char(tenth + 0x30);
send_char(data + 0x30);
}
else if(tenth>0)
{
send_char(tenth + 0x30); //0x30 added to become ASCII code
send_char(data + 0x30);
}
else send_char(data + 0x30); //0x30 added to become ASCII code
}

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) //looping 2000 times for getting average value
{
ADGO = 1; //ADGO is the bit 2 of the ADCON0 register
while(ADGO==1); //ADC start, ADGO=0 after finish ADC progress
result=ADRESH;
result=result<<8; //shift to left for 8 bit
result=result|ADRESL; //10 bit result from ADC

result_temp+=result;
}
result = result_temp/2000; //getting average value

}

unsigned short read_temp(void)
{
unsigned short temp;
temp=result;
return temp;

}

//==================subroutine DELAY==========================
void delay(unsigned short i)
{
for(;i>0;i--);
}
 

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