namqn
falleaf
#include <16F877A.h>
#fuses NOWDT,NOLVP,HS
#use delay (clock=20000000) //20Mhz
#use rs232(baud=2400, xmit=PIN_C6, rcv=PIN_C7, parity=N, bits=8)
#include <7Segments_Led_Display.c>
#include <init_timer0.c>
#byte TMR2 = 0x11
#byte PR2 = 0x92
#byte CCPR1L = 0x15
#byte CCPR1H = 0x16
#byte CCP1CON = 0x17
int16 i = 0;
int16 j = 0;
int16 counted_round_value = 0x00;
int16 update_counted_round_value = 0x00;
void convert_16bits_to_decimal_digit(int16 counted_round_value1) // calculate to display on 7_segment leg Max value 9999 or 0x270F
{
fourth_digit = counted_round_value1 / 1000;
third_digit = (counted_round_value1 % 1000) / 100;
second_digit = ((counted_round_value1 % 1000) % 100) / 10;
first_digit = ((counted_round_value1 % 1000) % 100) % 10;
}
#INT_TIMER0 // ngat timer0 tang bien dem len 1
void timer0_int()
{
counted_round_value++;
}
#INT_TIMER1 // ngat timer0 tang bien len 1
void timer1_int() // moi lan timer1 tran la 0.02s
{
TMR1_L = START_VALUE_TIMER1_L;
TMR1_H = START_VALUE_TIMER1_H;
if (j == 5){ // chu ki lay mau 0.02 * 5 = 0.1s
j = 0;
update_counted_round_value = counted_round_value*500 + get_timer0(); // so vong quay trong 1 phut
counted_round_value = 0;
printf("%ld\t",update_counted_round_value); // gui so xung cap nhat ve may tinh qua RS232
}
else
j++;
}
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,PR2,1); // 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 main()
{
int8 timer0_value;
set_tris_a(0xff);
init_PWM(19500);
init_timer0();
set_pwm1_duty(500); //set the duty cycle = 500*1/clock* T2div (T2div is in setup_timer2)
//= 500/20000000*1 = 25uS (~25%)
while(true){
convert_16bits_to_decimal_digit(update_counted_round_value); // tinh ra tung digit de hien thi
display_RPM_digit(); // hien thi tren led 7 doan
}
}
#include <16F877A.h>
void init_PWM(int16 frequency){
setup_ccp1(CCP_PWM); // initiate PWM
PR2 = 20000000/4/frequency - 1; // set PWM period
}
)
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