[gaumisa]

minh co tham khao doan code cua bluepine va lam nhu sau : minh da tao 4 nut nhan tren Vb : opencom , closecom , start , stop . Nut start se gui gia tri "a" , stop goi gia tri "b" .
Phan pic minh viet voi muc dich nhu sau :
dung ngat RDA de khi co 1 bye du lieu truyen tu may tinh ( ki tu "a" hay "b" ) , thi con pic dung hoat dong , nhay den gan gia tri do ( khong biet gia tri luc do la ma hay la ki tu nhi ) vao bien tam va kiem tra !
Dung ngat timer0 lam chu ki lay mau , va doc gia tri timer1 ( doc encoder ; chan ccp2 : gan voi tin hieu encoder )
chuong trinh nhu sau :

#include <16f877a.h>
#device *=16 ADC=10 
#fuses HS,NOWDT,NOPROTECT,PUT,BROWNOUT,NOLVP,NOCPD,NOWRT,NODEBUG
#use delay (clock = 20000000)
// Giao tiep vi dieu khien
#use rs232(baud=9600, parity=N,xmit=PIN_C6, rcv=PIN_C7 ) // Giao tiep RS232
#use i2c(master,fast,sda=PIN_C4,scl=PIN_C3,FORCE_HW)
#use fast_io(A)
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include<ctype.h>

#byte PR2 = 0x92

int16 e2;
int16 e1;
///////////////////////////////////////////////////////

int16 v_set = 200;

/////////////////////////////////////////////////////////
int16 v_cur;
int16 e_sum;
int16 e_del;
int16 flag_timer1;
int16 i=1 ;

///////////////////////////////////////////////////////////
unsigned long kp =5;
unsigned long ki = 0.62;
unsigned long kd = 10;
////////////////////////////////////////////////////////////


int16 pw_duty;

int16 temp_timer1;

char tam  ;
#byte TMR0 = 0x01 //timer0 REGISTER
#byte TMR1_L = 0X0E
#byte TMR1_H = 0X0F

#define START_VALUE_TIMER0 5 //tri khoi tao ban dau cua timer0 55, so xung dem duoc moi khi ngat la 255 - 5
#define START_VALUE_TIMER1 15535 //tri khoi tao ban dau cua timer1 65536-15536
#define dir PIN_B3 //or #bit dir = 0x6.3
#define brk PIN_B4
#define pwm PIN_C2
#priority RDA , timer0 
#INT_RDA// ngat khi nhan 1 bye 
RDA_isr()
{

tam=getc(); // lay gia tri tu cong  
}

#INT_TIMER0 // ngat timer0 tang bien len 1
void timer0_int()
{

   set_timer0(START_VALUE_TIMER0);
   i++ ;


   if ( i==50 )//neu nhu sau 50 lan tran cua timer0 (40ms:chu ki lay mau ) thi :

      temp_timer1 = get_timer1();
      set_timer1(START_VALUE_TIMER1);//lan tran thu 50 cua timer0 se set timer1
      v_cur =  8*(temp_timer1 - START_VALUE_TIMER1);
      i = 0;
      printf("%ld\t",pw_duty);
      flag_timer1 = 1;
}


void init_timer0()
{

setup_timer_0(RTCC_INTERNAL | RTCC_DIV_16); // timer0 dung xung ngoai va chia xung vao


setup_timer_1(T1_EXTERNAL | T1_DIV_BY_8); // 

set_timer0(START_VALUE_TIMER0);
set_timer1(START_VALUE_TIMER1);
enable_interrupts(INT_RDA);
enable_interrupts(INT_TIMER0);
enable_interrupts(INT_TIMER1);
enable_interrupts(GLOBAL);
}

void init_PWM(int16 frequency){

setup_ccp1(CCP_PWM); // initiate PWM
PR2 = 20000000/4/frequency - 1; // set PWM period

setup_timer_2(T2_DIV_BY_1,255,1); // initiate time 2 The cycle time will be (1/clock)*4*t2div*(period+1)
// (1/20000000)*4*1*(255+1) = 51.2 us( will over flow every 51.2 us, will intrup every 51.2 uS or 19.5 khz;

}

void cal_pid(){

long temp_kp;
long temp_ki;
long temp_kd;
e2 = v_set - v_cur;
e_sum += e2;
e_del = e2 - e1;
e1 = e2;

temp_kp = kp*e2;
temp_ki = ki*e_sum;
temp_kd = kd*e_del;
pw_duty +=temp_kp;

if (pw_duty <1000)
pw_duty += temp_ki;
if (pw_duty <1000)
pw_duty += temp_kd;
if (pw_duty <1000) // vi khi pw_duty <256 thi PWM chi dieu rong xung 8 bit / //chu khong phai 10 bit,
pw_duty = 256;
if (pw_duty >1000) // bao hoa
pw_duty = 1000;

printf(" \t%ld", v_cur); // truyen toc do xung ve may tinh hien thi tren Hyperterminal
}

void main()
{
int8 timer0_value;

init_timer0();
init_PWM(19500);

while(tam=='a') //vd 'a' ung voi nut quay thuan // khac a , khac (b) la stop
 {


      if (flag_timer1 ==1)
      {
            flag_timer1 = 0;
            cal_pid();
            output_low(pwm);// tat 4 con fet tuc thoi
            delay_us(20);
            output_low(brk);
            output_low(dir);
            delay_us(50);
            set_pwm1_duty(pw_duty);

     }
 }
}

Mong cac ban giup minh ! minh khong biet tai sao khi nhan nut tren VB , mach lai khong chay ! chuong trinh VB da kiem tra dung roi ! thanks nhieu !