Excel macro doesn't update correctly - vba

Question

i have created macro for excel but it seems somewhere i have done something wrong,
i want to fetch an image from a URL and then update it up to 1 second (more or less)
Sub GetPicture()
PictureURL = "This is where i put the URLi want"
Set MyPict = ActiveSheet.Pictures.Insert(PictureURL)
Cells(1).Value = Now
nextTime = Now + TimeValue("00:00:01")
End Sub
when i run the macro doesn't do anything,only when i press f5 the it updates as fast as i press f5,also what is the value to update less than 1 second ("00:00:01"),when i try ("00:00:0.5") it comes up with "run time error 13" "type mismatch"
Any help is very much apreciated.

Answer 1

In Excel, you can use VBA to trigger code that updates a Worksheet on specific intervals. The code below shows how you would activate a Timer each time the Worksheet is activated by a user. Whenever the Timer fires (on 1 second intervals here) this code updates Cell A1 in the ActiveSheet with the current Time.
To further customize, you would add code to the OnTimerMacro in order to update a Picture or whatever else you recurring task might be.
(Props to Hartmut Gierke for his post on the topic.)
Option Explicit
Dim Execute_TimerDrivenMacro As Boolean
Sub Start_OnTimerMacro()
Execute_TimerDrivenMacro = True
Application.OnTime Time + TimeValue("00:00:01"), ActiveSheet.Name & ".OnTimerMacro"
End Sub
Sub Stop_OnTimerMacro()
Execute_TimerDrivenMacro = False
End Sub
Public Sub OnTimerMacro()
If Execute_TimerDrivenMacro Then
' Do something e.g. put the actual time into cell A1 of the active sheet
ActiveSheet.Cells(1, 1).Value = Time
' At the end restart timer
Application.OnTime Time + TimeValue("00:00:01"), ActiveSheet.Name & ".OnTimerMacro"
End If
End Sub
Private Sub Worksheet_Activate()
'Start the timer driven method when opening the sheet
Start_OnTimerMacro
End Sub
Private Sub Worksheet_Deactivate()
'Stop the timer driven method when opening the sheet
Stop_OnTimerMacro
End Sub

Answer 2

if you would like the macro to repeat you have to put it in a do...until loop. The only problem, is that you can't really have the macro run all the time. There has to be a way to stop it. The do...until loop will help with this, but you have to come up with a reasonable exit from the loop. Can you give a little more background as to what you ultimately want this to do?
Also it sounds like you want the running of the macro to be triggered by something other than the pressing of F5. Can you explain when you would like to see it start?