16F181: can't wake up from sleep

[Acetronics2]

Hi, Navaid

1) think to reset the interrupt flag BEFORE allowing PORTB interrupt and entering sleep ...

2) not sure ... but , generally, change on portB need to read portB to clear the " Mismatch condition " ( @ wake-up ...)

3) enabling GIE sends you @ wake up ... to address 04 ( interrupt vector )
disabling GIE ...... to the next address of your program ( @sleep +1)
where a "nop" is highly recommended ( you did it fine ...).



a little example for a PIC 18F:

Here INT1 is the Wake-up "button"

Sommeil:

	LCDOUT $FE,1, "!!*BYE - BYE*!!"

	For I = 16 to 0	Step -1					'Animation arret
	
		LCDOUT 	$FE,$C0,REP "*"\I," "			'	...  4s 			
		PAUSE 250
		
	NEXT I
	


	PORTD = %00000000			' PortD à 0
	AlLCD = 1					' Coupure LCD
	ADCON0.0 = 0				' Désactivation ADC
	AlRef = 0					' Coupure Vref
	
	
	T3CON.0	= 0				' arret TMR3
	T1CON.0	= 0				' arret TMR1
	T0CON.7 = 0				' arret TMR0
	
	INTCON.7 = 0			' Wakeup sans interruptions
	
	INTCON3.0 = 0						' reset flag INT1
	INTCON3.3 = 1			' validation INT1 pour réveil

			
@ SLEEP
@ Nop						' Redémarrage par mise du contact


	INTCON3.3 = 0			'Neutralisation INT1
	INTCON3.0 = 0			'Reset Flag INT1

'*****************************************************************************
Wakeup: 'Début du Programme - reveil du PIC / Affichage Memoire
'*****************************************************************************
'
FLAGS 	= 0					' Validation Reset LCD
PORTD	= 0
Reveil 	= 1
LSelect	= 0
....

Alain

[Gusse]

3) enabling GIE sends you @ wake up ... to address 04 ( interrupt vector )
disabling GIE ...... to the next address of your program ( @sleep +1)
where a "nop" is highly recommended ( you did it fine ...).

Thanks Alain for this information. I have had lots of luck with my code when GIE option was enabled. Now I will disable it immediately.

Some lessons learnt again

BR,
-Gusse-

[Navaidstech]

Hi guys... thank you for the info.
Yes, I'm using a 16F818 chip... not really my choice but rather something that my buddy chose for his paintball gun and I'm stuck writing the software for it.

Anyway, thanks to your suggestions I'm getting close. However, what I've noticed is that on wake up the TMR1 interrupt is disabled.
I'm curious if this is normal and I just wonder if I need to re-enable it via the PIE register. I'll try that and see what happens.

[Archangel]

Some lessons learnt <u>again</u>

That happens to you too ? Welcome to my world

[Navaidstech]

OK guys... got it going. Here is the snippet of the the code around the sleep command. Works like a charm.
What I've done is I gave it a delay of 3 seconds from the closure of the switch to make sure PortB is undisturbed, then I took a snapshot of PortB (read it into a dummy variable), set up the interrupt and put the PIC to sleep. Once awoken, I read PortB again and cleared the flag.

Now here is another question... I'm also running Darrel Taylor's interrupt routine based on TMR1. I use it to flash a LED if a battery is low.
However, once the chip awakens from sleep, it would appear that this interrupt isn't working anymore (ie. no flashing).

I've noticed the same thing happens if I try to declare INTCON=00001000 at the top of the program... does this make sense?

    pause 3000
    dummyread=PortB
    intcon=%00001000
    @ sleep
    @ nop                       
    dummyread=PortB
    intcon.0=0