I used this code to generate long delay, i.e. 1 hour at 11,0592 MHz XTAL, using Timer0 interrupt.
This routine assign the AVR to toggle the LED when reach timeout.
This routine assign the AVR to toggle the LED when reach timeout.
| CODE |
include "m8535def.inc" .def smtr = r16 .def menuju1dtk = r17 .def cacahdtk = r18 .def cacahmnt = r19 .cseg .org 0 rjmp main .org 0x009 rjmp melimpah ;------------------------ISR------------------------------- melimpah: inc menuju1dtk cpi menuju1dtk, 43 in smtr, SREG sbrc smtr, 1 rcall sdh1dtk reti ;--------------------------------- sdh1dtk: clr menuju1dtk inc cacahdtk cpi cacahdtk, 60 in smtr, SREG sbrc smtr, 1 rcall sdh1mnt ret ;--------------------------------- sdh1mnt: clr cacahdtk inc cacahmnt cpi cacahmnt, 60 in smtr, SREG sbrc smtr, 1 rcall timeout ret ;---------------------------------- timeout: clr cacahdtk ;the delay reach timeout clr cacahmnt ; you can assign other in smtr, PORTD com smtr out PORTD, smtr ret ;----------------------------------------------------------------------- main: ldi smtr, high(RAMEND) out SPH, smtr ldi smtr, low(RAMEND) out SPL, smtr ;aktifkan timer clr menuju1dtk clr cacahdtk clr cacahmnt ldi smtr, 0b00000101 out TCCR0, smtr ldi smtr, 1 out TIMSK, smtr ;ldi smtr, 250 ;out TCNT0, smtr sei ser smtr out DDRD, smtr ldi smtr, 0xF0 out PORTD, smtr loop: rjmp loop ;this is your main routine |
The important values are :
43 in cpi menuju1dtk, 43 -> obtained by calculate 1 second / tme needed to overflow of Timer0
60 in cpi cacahdtk, 60 -> to obtain 1 minute delay (60 seconds)
60 in cpi cacahmnt, 60 -> to obtain 1 hour delay (60 seconds)
The delay can be longer if you change the above values with the higher number.