Hi guys,
I have been trying to create a basic application that goes into a sleep state during low power periods. It must use the timer during this time to increment and keep time. I have been having issues that the unit actually restarts when waking it up after it has been in a sleep state for several minutes. Initially I am simply using the PA2 Pin for testing the state, attaching to ground or pulling it high externally through a pin interrupt.
If i wake up it before 2-3 mins, no issues and the unit continues under normal operation.
Any ideas on what I may be doing wrong?
I am using the Atmega324PA running at 8MHZ with the fuses: L:0xFF H:0xD7 E:0xFE
#define F_CPU 8000000UL #define UBRR_VALUE 16 #include#include #include #include #include uint16_t tim = 0; void StartSleep() { sei(); set_sleep_mode(SLEEP_MODE_PWR_SAVE); sleep_mode(); } int main(void) { //init uart /* Set the baud rate */ UBRR0H = (uint8_t)(UBRR_VALUE>>8); UBRR0L = (uint8_t)UBRR_VALUE; UCSR0A |= (1<<U2X0); UCSR0B = ( ( 1 << RXCIE0 ) | ( 1 << RXEN0 ) | ( 1 << TXEN0 ) ); UCSR0C |= (1<<UCSZ01)|(1<<UCSZ00); //For devices with Extended IO //init pin interrupt DDRA &= ~(1<<PA2); PCICR |= (1<< PCIE0); PCMSK0 |= (1<< PCINT2); //init timer2 TCNT2 = 0; ASSR |= (1<< AS2); //enable external clock TIMSK2 |= (1<<TOIE2); TCCR2B |= (1<<CS22)|(1<<CS21); tim = 0; //init LED's UDR0 = 'R'; DDRC |= (1<<PC5); PORTC |= (1<<PC5); char x[6]; sei(); while(1) { _delay_ms(2000); ltoa(tim,x,10); for(uint8_t i = 0;i < 6;i++) { if (x[i] == 0) break; _delay_ms(1); UDR0 = x[i]; } _delay_ms(1); UDR0 = '\n'; } } ISR(TIMER2_OVF_vect) { tim+=2; if (!(PINA & (1<<PA2))) { //If the device has no mains power - start sleep operation StartSleep(); } } ISR(PCINT0_vect) { if (!(PINA & (1<<PA2))) { //If the device has no mains power - start sleep operation StartSleep(); } else { UDR0 = 'w'; } }
