Problem with Timer2 and Timer0 interrupt

mutevaggil · Joined: 29 May 2008 Posts: 8

hi everyone. i got a problem.

here is my timer adjustments of timer0:

Ttelmah · Guest

Do some searches here.
The problem is fundamentally, that interrupts take _time_. With a counter advancing every 8 instruction times, the timer will probably already have advanced by several counts, before you get to your instruction setting the count. When you then set the timer, this advance is 'lost', so the timer is then seen to run slow.
Preferably, either use a timer that supports resetting at a count in hardware (timer2), or adjust your code so you don't have to reset the timer value. As a 'worst case' solution, _add_ your required offset to the value read from the timer (this can still give errors if the timer increments between the read and the write).
There have been a huge number of threads here about this, and different methods of avoiding problems.

Best Wishes

mutevaggil · Joined: 29 May 2008 Posts: 8

thanks ttelmah,

i listened your advice and did some searches here. you really answered hundreds of time for the same problem. and of them worked for me.

i just kept PR2 short. i mean:

Instead of TIMER2(DIV_BY_1, 124, 8) //100us,

TIMER2(DIV_BY_4,24, 10) //100 us worked very well.

i am writing this here because this may be help any other people who face to same problem.

thanks.