gambar 1. Simulasi timer 1 dengan proteus
Perhitungan timer :
Time value = (Required delay / clock value)-1
Ø Required delay : waktu yang diinginkan
Ø Clock value : clock timer1 periode
example :
- waktu yang di inginkan adalh 1 detik
- ext clock 8 Mhz
- clock value 7,813 Khz = 7813 Hz
Time value = (1s/(1/7813Hz))-1 diketahui periode adalah T = 1/F
Time value = (1s x 7813) - 1
Time value = 7812 = 0x1e84
Berikut contoh pengaturan timer1 :
gambar 2. konfigurasi chip mikrokontroller
gambar 3. konfigurasi timer 1 dengan ctc mode
berikut contoh program yang telah dibuat :
/*****************************************************
This program was produced by the
CodeWizardAVR V2.05.3 Standard
Automatic Program Generator
© Copyright 1998-2011 Pavel Haiduc, HP
InfoTech s.r.l.
http://www.hpinfotech.com
Project :
Version :
Date
: 9/22/2014
Author :
fahmibnu
Company :
Comments :
Chip type
:
ATmega8
Program type
: Application
AVR Core Clock frequency : 8.000000
MHz
Memory model
: Small
External RAM size
: 0
Data Stack size
: 256
*****************************************************/
#include <mega8.h>
#include <stdlib.h>
#include <delay.h>
#define t_enter
PINC.3
#define
t_down
PINC.2
#define
t_up
PINC.1
#define t_pause
PINB.5
int
count_time,temp,menit,temp_menit,up,down;
char
counter_time[5],temperature[5],buf_menit[5];
void menu();
// Alphanumeric LCD functions
#include <alcd.h>
// Timer1 output compare A interrupt
service routine
interrupt [TIM1_COMPA] void
timer1_compa_isr(void)
{
// Place your code here
count_time--;
//counter down per 1 detik
if(count_time < 0
&& menit != 0)
{
menit--;
count_time = 59;
}
else if(count_time <
0 && menit == 0)
{
menit = 0;
count_time = 0;
TCCR1B = 0;
}
}
// Declare your global variables here
void main(void)
{
// Declare your local variables here
// Input/Output Ports initialization
// Port B initialization
// Func7=In Func6=In Func5=In Func4=In
Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=P State4=T
State3=T State2=T State1=T State0=T
PORTB=0x20;
DDRB=0x00;
// Port C initialization
// Func6=In Func5=In Func4=In Func3=In
Func2=In Func1=In Func0=In
// State6=T State5=T State4=T State3=P
State2=P State1=P State0=T
PORTC=0x0E;
DDRC=0x00;
// Port D initialization
// Func7=In Func6=In Func5=In Func4=In
Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T
State3=T State2=T State1=T State0=T
PORTD=0x00;
DDRD=0x00;
// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: Timer 0 Stopped
TCCR0=0x00;
TCNT0=0x00;
// Timer/Counter 1 initialization
// Clock source: System Clock
// Clock value: 7.813 kHz
// Mode: CTC top=OCR1A
// OC1A output: Discon.
// OC1B output: Discon.`
// Noise Canceler: Off
// Input Capture on Falling Edge
// Timer1 Overflow Interrupt: Off
// Input Capture Interrupt: Off
// Compare A Match Interrupt: On
// Compare B Match Interrupt: Off
/// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: Timer2 Stopped
// Mode: Normal top=0xFF
// OC2 output: Disconnected
ASSR=0x00;
TCCR2=0x00;
TCNT2=0x00;
OCR2=0x00;
// External Interrupt(s) initialization
// INT0: Off
// INT1: Off
MCUCR=0x00;
// Timer(s)/Counter(s) Interrupt(s)
initialization
TIMSK=0x10;
// USART initialization
// USART disabled
UCSRB=0x00;
// Analog Comparator initialization
// Analog Comparator: Off
// Analog Comparator Input Capture by
Timer/Counter 1: Off
ACSR=0x80;
SFIOR=0x00;
// ADC initialization
// ADC disabled
ADCSRA=0x00;
// SPI initialization
// SPI disabled
SPCR=0x00;
// TWI initialization
// TWI disabled
TWCR=0x00;
// Alphanumeric LCD initialization
// Connections are specified in the
// Project|Configure|C
Compiler|Libraries|Alphanumeric LCD menu:
// RS - PORTD Bit 2
// RD - PORTD Bit 3
// EN - PORTD Bit 4
// D4 - PORTD Bit 1
// D5 - PORTD Bit 5
// D6 - PORTD Bit 6
// D7 - PORTD Bit 7
// Characters/line: 16
lcd_init(16);
// Global enable interrupts
#asm("sei")
count_time = 0;
menit = 0;
lcd_gotoxy(0,0);
lcd_putsf(" :: Welcome ::
");
lcd_gotoxy(0,1);
lcd_putsf("
Fahmibnu-ELK ");
delay_ms(1000);
lcd_clear();
while (1)
{
// Place
your code here
itoa(menit,buf_menit);
if(menit < 10)
{
lcd_gotoxy(5,0);
lcd_putsf("0");
lcd_gotoxy(6,0);
lcd_puts(buf_menit);
}
else if(count_time > 9)
{
lcd_gotoxy(5,0);
lcd_puts(buf_menit);
}
lcd_gotoxy(7,0);
lcd_putsf(":");
itoa(count_time,counter_time);
if(count_time < 10)
{
lcd_gotoxy(8,0);
lcd_putsf("0");
lcd_gotoxy(9,0);
lcd_puts(counter_time);
}
else if(count_time > 9)
{
lcd_gotoxy(8,0);
lcd_puts(counter_time);
}
lcd_gotoxy(0,1);
lcd_putsf(" Membuat Timer");
menu();
delay_ms(50);
}
}
void menu()
{
if (t_up == 0)
{
up = 1;
if(up == 1)
{
delay_ms(50);
count_time++;
if(count_time > 59)
{
menit++;
count_time = 0;
}
up = 0;
}
t_up = ~t_up;
lcd_clear();
}
else if(t_down == 0)
{
down = 1;
if(down == 1)
{
delay_ms(50);
count_time--;
if(count_time < 0)
{
menit--;
count_time = 59;
}
down = 0;
}
t_down = ~t_down;
lcd_clear();
}
else if(t_enter == 0)
{
while(t_enter == 0);
TCCR1B = 0x0D; //timer1 is on
t_enter = ~t_enter;
}
else if(t_pause == 0)
{
while(t_pause == 0);
TCCR1B = 0x00; //timer1 is off
t_c = ~t_c;
}
}
