🚀 go-pugleaf

Paul at NCF wrote:
 >
 > I've got a timer system that uses GetTickCount for calculate the
 > number ticks (in milliseconds), for timer calculations etc.
 >
 > This works fine on my laptop, which is quite a good HP running XP.
 > But on the target system running NT and is a lower spec PC, its not
 > accurate at all; usually timers are 10-20% longer (eg. A 15 second
 > timer ends up being about 18).

Are you doing something like this?

... {
    SetTimer( NULL, 0, 15000, TimerProc );
}

TimerProc(..., dwTime ) {
     static DWORD dwLastTime=0;
     SetTimer( NULL, 0, 15000, TimerProc );

     if( dwLastTime ) {
         /*
         dwTime - dwLastTime
         should now be approx. 15000, unless a wrap around occured,
         but you get 18000 ?
         */
     }
     dwLastTime = dwTime;
}

 > I've tried using the performance counter as a more accurate system,
 > but I'm not getting very good results even on my HP.
 >
 > Has anyone got any clues or ideas for a timer calculations for
 > handling timers of various lengths?

I used QueryPerformanceCounter() and QueryPerformanceFrequency() a few 
years back to measure RPM's in an engine (connected to a pin in the 
serial-port on a Windows NT4 box). We test-fed the application up to 
something like 300000 pulses/s (~0.003 ms between pulses) which it 
measured quite nicely.

> PS.  my perception of accuracy is based on the Now() time logged in a file 
> activitie (hours,mins,secs,milliseconds).

Hmmm, may we see some code?

Kind regards,
Ted Lyngmo