Sleep functon from kernel Library works inconsistent in VBA

I have a program that uses the sleep function in VBA from the kernel library.

It has a tendency to work inconsistently.  All of the sudden it will start to run really slowly.  I will have to turn the time down from 1 to .1 in order to get it to work at the speed it used to.  

There are not any other programs running that would "slow" it down.  I am running the application on a core 2 processor.

Is there any other functions I can use to delay something by a millesecond?  Perhaps something that may act more consistent.

JOe K.
Public timerCounter As Integer
Private Declare Sub sapiSleep Lib "kernel32" Alias "Sleep" (ByVal dwMilliseconds As Long)
Sub sSleep(lngMilliSec As Long)
    If lngMilliSec > 0 Then
        Call sapiSleep(lngMilliSec)
    End If
End Sub

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Who is Participating?
Rey Obrero (Capricorn1)Connect With a Mentor Commented:
i am just using

Public Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

and to delay i just use

sleep 500  ' or any other value
Jim Dettman (Microsoft MVP/ EE MVE)PresidentCommented:
  Your not not going to get that fine of control outside of running in the OS kernel.  A thread shift alone can easily takes 15ms or more.  You'd have to be running in a process that was no swapable and with a high priority.

  I'm curious; what are you trying to do that takes such fine control?

ClaudeWalkerAuthor Commented:
Using the Alias and calling the other sub was the slowing down issue as far as I can tell. Because the problem is intermittent only time will tell.

Here is the code I am using sleep for.

I created a "screen saver" to prevent burnin on our IO board screen.  Runs every 30 minutes and it cycles from red to blue to green to yellow to blue to red again.  It takes about 30 seconds  Then displays whose gone and whose in the office.  

If timerCounter = TIMERLIMIT Then
        For v = 1 To 36
            For Each ctl In Me.Controls
                If ctl.ControlType = acLabel Then
                    numCtls = numCtls + 1
                    If v = 1 Then
                        ctl.Caption = ""
                        backCol = 10001000
                        ctl.BorderStyle = 0
                    End If
                    If v = 36 Then
                        ctl.BorderStyle = 1
                    End If
                    ctl.BackColor = backCol
                End If
                If v < 19 Then
                    backCol = backCol + 20
                    backCol = backCol - 20
                End If
                Sleep 3
            Next ctl
        Next v
        timerCounter = 0
    End If

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ClaudeWalkerAuthor Commented:
I moved it to a slower computer and sleep didn't work as well.  It seemed to round up after .5 for the number of milleseconds.  I .5 was close but I needed more like .7 and it went as slow as 1.

I made a ghetto solution.

For ghettoTimer = 1 to 150000

next ghettoTimer

It gave much more control and seemed to work well.

JOe K.
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