[mahmosha]

hi all i was wondering about how to make a code that calculates remote control tv /AC but the problem always how to make the decode for the first pulse time????
i decided to use timer0 as a pulse calculator and timer1 as a time decoder (for the first pulse)
the idea of the program is setting timer0 = 255 at the start of the code so when a pulse come it goes to interrupt and make timer1 start counting as a timer but the proplem is that it wont stop except for its interrupt how to make timer1 stop counting as a timer when the pulse ends? i though about making timer0 =255 when the interrupt happens it goes 255 so the next pulse's interrupt will make the timer1 stop counting but the problem that the timer zero counts on the Falling edge according for the receiver which becomes low with a signal so it will be a mismatch in the time because it takes about 13us to go from hight to low correct me if i am mistaking but i really need help if you can help me please do Greeting...

[ماجد عباس محمد]

اقتباس المشاركة الأصلية كتبت بواسطة mahmosha hi all i was wondering about how to make a code that calculates remote control tv /AC but the problem always how to make the decode for the first pulse time???? i decided to use timer0 as a pulse calculator and timer1 as a time decoder (for the first pulse)

This is called "Learn Mode" so the micro will have no other job but to decode the incoming signal, which is a small time.
So it is better to let the interrupt routine just checks when the input signal ends then go back to main program to read the counter and save it somewhere and reset it prepare for next one and do what it has to do till the next interrupt

the idea of the program is setting timer0 = 255 at the start of the code so when a pulse come it goes to interrupt and make timer1 start counting as a timer but the proplem is that it wont stop except for its interrupt how to make timer1 stop counting as a timer when the pulse ends? i though about making timer0 =255 when the interrupt happens it goes 255 so the next pulse's interrupt will make the timer1 stop counting but the problem that the timer zero counts on the Falling edge according for the receiver which becomes low with a signal so it will be a mismatch in the time because it takes about 13us to go from hight to low correct me if i am mistaking but i really need help if you can help me please do Greeting...

it is difficult this way as the pulse has some time HI and another time LO and you either interested in the HI period OR LO ONLY not both depending on the schematic you use