//chuong trinh viet cho VDK PIC16F877A de do du lieu ADC tu kenh AN0

//cam bien nhiet su dung la lm35 (10mv/1doC)

//hien thi gia tri nhiet do tren 2 led 7 doan

//portB noi voi cac doan

//chan c0,c1 cua portC quet led

//-------------------------------------------------------------------

#include"16f877a.h"

#include"def_877a.h"

#device *=16 adc=10  //chon dc 10 bit

#use delay(clock=4mhz)

//ding nghia ma 7 doan

const int ma_7doan[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};

// khai bao bien

int adc_read,chuc,don_vi,chuc_7doan,don_vi_7doan;

//chuong trinh con hien thi

void hien_thi()

{

portb=don_vi_7doan;

rc0=0;

delay_us(100);

rc0=1;

portb=chuc_7doan;

rc1=0;

delay_us(100);

rc1=1;

}

//chuong trinh chinh

void main()

{

//thiet lap cac dau vao ra

trisb=0;  //dat port b lam dau ra

trisc0=0;

trisc1=0;   //dau ra quet led

trisa0=1;   //dau vao analog

//------------------------

setup_adc_ports(an0);

setup_adc(adc_clock_internal);

// o day ta su dung adc 10 bit voi vref+=5V, vfef-=0v

// ma 1 do C ung voi 10mv ( dung cam bien LM35)

// 5000mv - - - voi - - - 1024 ( 2^10)

// 10mv - - - voi x >>> x=10mv*1024/5000mv=2.048 so dem

while(true)

   {

adc_read=read_adc();

adc_read=adc_read/2.048;

chuc=adc_read/10;

chuc_7doan=ma_7doan[chuc];

don_vi=adc_read%10;

don_vi_7doan=ma_7doan[don_vi];

hien_thi();

   }

}