Power saving in PIC18F4520

[hez_91]

Hello,

I am working on a Anti-House Breaking System project which operates 24 hour/day surveillance.
I am planning to put it on sleep mode until the PIR sensor or Glass-Break sensor detects a break-in. How can this be done? (if possible)

I am aware of the 7 different operating modes but unsure of whether to use the Sleep or Idle modes and how to implement them.

I am also not sure of whether to use the watchdog timer or PIE interrupt to wake the PIC out of sleep mode.

Any help would be appreciated

#include <p18f4520.h>
#include <delays.h>

void main() {
//Initialisation of Analog and Digital and Port pins

ADCON1 = 0b00001111;	// set as Digital I/O
TRISA = 0b00000011;
TRISB = 0b00000000;	

                                                                                                 
while(1) {
if(PORTAbits.RA0=~PORTAbits.RA0) // Check for PIR Sensor
{
PORTB = 0b00000010; // Activate alarm
}
else
{
PORTB = 0b00000000;

}

if(PORTAbits.RA1=~PORTAbits.RA1) // Check for Glass-Break Sensor
{
PORTB = 0b00000010; // Activate alarm
}
else
{
PORTB = 0b00000000; 
}


}
}

 

[Kurenai_ryu]

firstly, do your program needs something more? or it's just detect input pulse and then bang! output on PORTB...
so to rearm the system just a reset?

does it will have some user interface? (lcd,keypad)
if not,
you can use the PIC INTs inputs, and "wake" from a Sleep() with no more business...(no watchdog no other interrupt) even, yo don't need an interrupt routine, just enable the interrupts but not the global interrupt bit...

 

[hez_91]

Thanks for the tips,

I had changed the code to wake up from sleep through a INT input.

However, the interrupt only runs once, with or without sleep.

Can anyone help me with this problem?

#include <p18f4520.h>
#include <stdlib.h>
#include <delays.h>

void InterruptHandlerLow(void);

#pragma code InterruptVectorLow = 0x18
void InterruptVectorLow(void){

_asm
	goto	InterruptHandlerLow
_endasm

}
#pragma code

#pragma interruptlow InterruptHandlerLow

void InterruptHandlerLow(void){

if(INTCON3bits.INT1IF = 1)
{
	PORTBbits.RB0 = 1; //Turn on Red LED
    Delay10KTCYx(200);
    PORTBbits.RB0 = 0; //Turn off Red LED
	INTCON3bits.INT1IF = 0;
}
}
void main()
{

OSCCONbits.IDLEN = 0;

TRISA = 0xff;
TRISB = 0b11110110;
TRISC = 0xff;
TRISD = 0xff;
TRISE = 0xff;

T0CON = 0b10000010;
PORTA = 0;
PORTB = 0;

INTCONbits.GIEH =0;
INTCONbits.GIEL =0;
RCONbits.IPEN = 1;

INTCON2bits.INTEDG1 = 1;

INTCON3bits.INT1IP = 0;
INTCON3bits.INT1IF = 0;
INTCON3bits.INT1IE = 1;

INTCONbits.GIEL = 1;
INTCONbits.GIEH = 1;

// Sleep();
PORTBbits.RB3 = 1; //Turn on Green LED

while(1);


}