Timing out DT's Blinking Led

[tazntex]

I've been experimenting, if one could call it that, with Darryl Taylor's Interrupts and have another question.

How could I use the Blinky Led example to execute the toggleled but time itself out after a few seconds?

'************************************************* ****
Example from Darryl's website:
LED1 VAR PORTB.1

INCLUDE "DT_INTS-14.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts

ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler TMR1_INT, _ToggleLED1, PBP, yes
endm
INT_CREATE ; Creates the interrupt processor
ENDASM

T1CON = $31 ; Prescaler = 8, TMR1ON
@ INT_ENABLE TMR1_INT ; enable Timer 1 interrupts

Main:
PAUSE 1
GOTO Main

'---[TMR1 - interrupt handler]--------------------------------------------------
ToggleLED1:
TOGGLE LED1
@ INT_RETURN


'************************************************* ****
I thought at first writing a
main:
@ sleep
@ nop
goto main

ToggleLED1:
TOGGLE LED1
REPEAT
i = i +1
UNTIL i > 10
If i >= 10 then
T1CON = $0
@ INT_RETURN

Well that through a wrench in my work, because for one it through off the led timing, makes it Slowwww... and second it just repeats itself because later I tried to add a:
main:
High LED1
pause 250
LOW LED1
@ sleep
@ nop
goto main

and I see the toggling of the led with the pause I added.

Anyhow, I am still tinkering and haven't burn anything up yet. Thanks for any suggestions

[Bruce]

You could increment a couter variable in your interrupt, and just disable the interrupt after x number of counts.

The big problem however is with Timer1. It stops working during sleep since the oscillator is shut off in sleep. You would need to setup Timer1 with an external oscillator for it to run during sleep periods.

[tazntex]

Thanks Bruce for your suggestion.
The idea I was toying with was to toggle the led for a few moments then time out and go to sleep, ...I then added to the main: the high led/low led to signal that it had returned from the ToggleLed1. Then sleep....

Thanks again for the reply.

[Bruce]

The reason your first version is WAY slow is because Timer1 shuts down during sleep. When the WDT wakes it from sleep, you only have 1 nop and the GOTO Main instruction cycles before it goes back to sleep.

So it takes Timer1 a really long time to increment to overflow with a prescaler of 1:8.

Just increment a variable in the interrupt handler, and check it for a certain value in Main. When it reaches the pre-set value, disable Timer1 and go to sleep.

You can re-enable it as needed.