void lp_ticker_set_interrupt(timestamp_t timestamp)
{
uint64_t timestamp_ticks;
uint64_t current_ticks = RTC_CounterGet();
timestamp_t current_time = ((uint64_t)(current_ticks * 1000000) / (LOW_ENERGY_CLOCK_FREQUENCY / RTC_CLOCKDIV_INT));
/* calculate offset value */
timestamp_t offset = timestamp - current_time;
if(offset > 0xEFFFFFFF) offset = 100;
/* map offset to RTC value */
// ticks = offset * RTC frequency div 1000000
timestamp_ticks = ((uint64_t)offset * (LOW_ENERGY_CLOCK_FREQUENCY / RTC_CLOCKDIV_INT)) / 1000000;
timestamp_ticks += current_ticks;
/* RTC has 24 bit resolution */
timestamp_ticks &= 0xFFFFFF;
/* check for RTC limitation */
if((timestamp_ticks - RTC_CounterGet()) >= 0x800000) timestamp_ticks = RTC_CounterGet() + 2;
/* Set callback */
RTC_FreezeEnable(true);
RTC_CompareSet(0, (uint32_t)timestamp_ticks);
RTC_IntEnable(RTC_IF_COMP0);
RTC_FreezeEnable(false);
}
void lp_ticker_set_interrupt(timestamp_t timestamp)
{
RTC_IntDisable(RTC_IF_COMP0);
RTC_IntClear(RTC_IF_COMP0);
RTC_FreezeEnable(true);
RTC_CompareSet(0, (uint32_t) (timestamp & RTC_MAX_VALUE));
RTC_FreezeEnable(false);
RTC_IntEnable(RTC_IF_COMP0);
}
void lp_ticker_free()
{
/* Disable the RTC if it was inited and is no longer in use by anyone. */
if (rtc_inited) {
NVIC_DisableIRQ(RTC_IRQn);
RTC_Reset();
CMU_ClockEnable(cmuClock_RTC, false);
rtc_inited = false;
}
RTC_FreezeEnable(false);
}