BÀI 33 : BĂM XUNG SỬ DỤNG BIẾN TRỞ PIC16F877A XC8

Lý thuyết về ADC và PWM các bạn xem lại các bài đăng trước (ADC bài 22, PWM bài 27).

- Đây là ảnh mô phỏng protues.

- Đây là code chương trình.

#include <stdio.h>

#include <stdlib.h>

#include <xc.h>

#include "pwm.h"

#define _XTAL_FREQ 4000000

// CONFIG

#pragma config FOSC = HS        // Oscillator Selection bits (HS oscillator)

#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)

#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)

#pragma config BOREN = OFF      // Brown-out Reset Enable bit (BOR disabled)

#pragma config LVP = OFF        // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)

#pragma config CPD = OFF        // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off)

#pragma config WRT = OFF        // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control)

#pragma config CP = OFF         // Flash Program Memory Code Protection bit (Code protection off)

void PWM(void);

void ADCinit (void);

unsigned int ReadADC (void);

unsigned int ADCvalue = 0;

unsigned int duty=0;

void main(void) 

{

    ADCinit();

    PWM();

    while(1)

    {

        ADCvalue = ReadADC();

        duty = (ADCvalue/1023.0)*100.0;//while

        PWM1_Duty(duty);        

    }

}

void PWM(void)//ham khai bao pwm

{

    PWM1_Init_Fre(1000);

    PWM1_Duty(duty);//while

    PWM1_Start();

}

void ADCinit (void)// adc

{

    // chon tan so clock cho bo adc

    ADCON1bits.ADCS2 = 0, ADCON0bits.ADCS1 = 0,ADCON0bits.ADCS0 = 1;

    // chon kenh adc la kenh an0

    ADCON0bits.CHS2 = 0, ADCON0bits.CHS1 = 0, ADCON0bits.CHS0 = 0;

    // chon cach luu data

    ADCON1bits.ADFM = 1;

    // cau hinh cong vao

    ADCON1bits.PCFG3 = 1,  ADCON1bits.PCFG2 = 1,  ADCON1bits.PCFG1 = 1,  ADCON1bits.PCFG0 = 0;

    // cap nguon cho khoi adc

    ADCON0bits.ADON = 1;

}

unsigned int ReadADC (void)// doc len 7 doan

{

    unsigned int TempValue = 0;

    ADCON0bits.GO_nDONE = 1;

    while(ADCON0bits.GO_nDONE);

    TempValue = ADRESH*256 + ADRESL;

    return (TempValue);

}

- Link download project Click here