Pulse generation help required

[HenrikOlsson]

Hi again,
Im sorry... I just returned from work and checked the datasheet for the 'F84 and it doesn't have TMR1. It does, however have TMR0 and a prescaler that you may be able to use as long as you turn off the WDT.

If I where you I'd consider changing that 'F84 to something like the 'F628 if at all possible. If you NEED to run it on the 'F84 let us know...

Here's a quick non tested example of how you could use TMR1 on 'F628. It doesn't use interupts it only polls the TMR1 interupt flag to se if it has rolled over.

Loop:
    If PortB.1 = 0 then Goto Loop       'Wait here until PortB.1 goes high.


SetPulse:
   'Preload TMR1 ((232*256) + 143 = 59535)
   TMR1H = 232
   TMR1L = 143
   High PortB.1              'Set the output.
   T1CON.0 = 1             'Start the tmr.

WaitForTimeOut:
   If PIR1.0 = 1 then      'The time is up...
       Low PortB.0          'Turn off the output
       T1CON.0 = 0         'Stop TMR1
       PIR1.0 = 0            'Reset the TMR1 Interupt Flag            
       TMR1H = 232        'Reload TMR1 so it ready for the next pulse
       TMR1L = 143
       Goto Loop
   Endif

   'Do your other stuff here.....
   'Don't use any time consuming pauses etc.
Goto WaitForTimeOut

Hope that helps a bit more than my first suggestion.
/Henrik Olsson.

[Muzza]

Hendrik, thanks for the speedy advice.
Looks like what I need to do to make my implementation work.
I will go to the F628 as you suggest.
I am new to this (PICs and PBP) and just learned heaps through investigating your suggested code and studying the datasheets to see how it works.
Thanks heaps for that.
Best Regards.
Murray