/** Blink led as a south cardinal mark.
* Pattern: ^_^_^_^_^_^_^^^___
*
* Exemple usage:
* \code
* blink(PB0);
* \endcode
*
* @param pin the pin of the led
*
*/
void blink (int pin)
{
int i;
set_AC(0);
// set a timer0
TIMSK |= _BV(TOIE0); // enable interrupt on overflow
TCCR0B |= _BV(CS00); // set prescaler to CLKio/(No prescaling)
PRR &= ~ _BV(PRTIM0); // enable Timer0 module
for (i=0; i<6; i++)
{
PORTB |= _BV(pin); // on
idle_sleep (333, 1);
PORTB &= ~ _BV(pin); // off
idle_sleep (333, 1);
}
PORTB |= _BV(pin); // on
idle_sleep (3000, 1);
PORTB &= ~ _BV(pin); // off
idle_sleep (3000, 1);
// remove timer0
PRR |= _BV(PRTIM0); // disable Timer0 module
TIMSK &= ~ _BV(TOIE0); // disable interrupt on overflow
TCCR0B &= ~ _BV(CS00); // unset prescaler to CLKio/(No prescaling)
set_AC(1);
} // blink()
int main(void)
{
DDRB = 0xFF; // All port B are outputs
/*
* Configure TIMER0
* - Enable timer0 interrupt
* - Set prescaler
*/
TIMSK |= _BV(TOIE0);
TCCR0B |= _BV(CS02);
sei();
while (1)
{
idle_sleep(6000, 256);
PORTB = 0xFF;
idle_sleep(1000, 256);
PORTB = 0x00;
}
}
void cpu_idle(void)
{
while (1) {
tick_nohz_idle_enter();
local_irq_disable();
while (!need_resched()) {
idle_sleep();
/* interrupts wake us up, but aren't serviced */
local_irq_enable(); /* service interrupt */
local_irq_disable();
}
local_irq_enable();
tick_nohz_idle_exit();
schedule();
}
}