PIC18F458 - sleep - interrupts - battery

[billyboy72]

Hi to everybody,

I have drawn near from few to the PICs and, as such, I am facing the first problems that I expose You following. My target is to make to sleep the PIC when the power supply falls and to use a battery to keep on developing some activities: particularly if in condition of battery feeding occurs an external interrupts I want to wake up the micro and to write a data in eeprom for then to return in sleep fashions. Obviously to the restoration of the power supply there is the systematic awakening. In order to resolve this last point I connect the Vcc to the pin RB1.

Someone has suggestions

Thanks in advance

[Ttelmah]

[billyboy72]

Hi Ttelmah,

thanks for your kind suggestion, I will immediately verify the possibility to insert the suitable IC. Nevertheless I would like to add to the painted scenery in the preceding intervention that I have provided to the input PIN B1 of an opportune passive filter has for avoiding the rebounds of the power supply. Following amount carried over an example of code that reproduces the situation:
-------------------------------------------------------------------------------------
// global flag to send processor into sleep mode
short sleep_mode;
short power_down;
int poweroff;

// external interrupt when power supply is switched off
#INT_EXT1
void ext1_isr() {
if(!power_down)
{
write_eeprom(2,0x0F);
delay_us(10);
write_eeprom(1,0x0F);
delay_us(10);
printf("The processor sleep.\r\n");
++poweroff;
write_eeprom(0,poweroff);
delay_us(10);

ext_int_edge(L_TO_H);
}
else
{
write_eeprom(2,0xFF);
delay_us(10);
write_eeprom(1,0xFF);
delay_us(10);
ext_int_edge(H_TO_L);
printf("The processor run.\r\n");
}
if(!input(PIN_B0)) /
power_down=TRUE;
delay_ms(100); // debounce button
}

// main program that increments counter every second unless sleeping
void main() {
long counter;
byte sleep_status;
byte power_status;
ext_int_edge(H_TO_L); // init interrupt triggering for button press
enable_interrupts(INT_EXT1);// turn on interrupts
enable_interrupts(GLOBAL);

printf("\n\n");

counter=0; // reset the counter
while(TRUE)
{


poweroff=read_eeprom(0);
if(poweroff==255)
{
write_eeprom(0,0);
delay_us(10);
poweroff=0;
}

sleep_status=read_eeprom(1);
if(sleep_status==255)
{
sleep_mode=FALSE;
}
else
{
sleep_mode=TRUE;
}

power_status=read_eeprom(2);
if(power_status==255)
{
power_down=FALSE;
}
else
{
power_down=TRUE;
}


if(sleep_mode)
{

enable_interrupts(INT_EXT1);
ext_int_edge(L_TO_H);
sleep();
}
printf("The count value is: %5ld \r\n",counter);
counter++;
if(counter==10)//
{
counter=0;//
printf("The eeprom_poweroff value is: %d \r\n",read_eeprom(0));

}
}
}
-------------------------------------------------------------------------------------

Thanks in advance