sf
Dependencies: LPC1114_WakeInterruptIn
Fork of WakeUp by
Device/WakeUp_STM_RTC.cpp
- Committer:
- Sissors
- Date:
- 2015-04-22
- Revision:
- 17:49d9e3a3e904
- Parent:
- 15:b2a710aca356
- Child:
- 20:68f2ee917691
File content as of revision 17:49d9e3a3e904:
#ifdef TARGET_STM #include "WakeUp.h" #include "rtc_api.h" #define BYTE2BCD(byte) ((byte % 10) | ((byte / 10) << 4)) #define EXTI_RTC_LINE (1 << 17) //Most things are pretty similar between the different STM targets. //Only the IRQ number the alarm is connected to differs. Any errors //with RTC_IRQn/RTC_Alarm_IRQn in them are related to this #if defined(TARGET_M4) || defined(TARGET_M3) #define RTC_IRQ RTC_Alarm_IRQn #else #define RTC_IRQ RTC_IRQn #endif //Disabling the Backup Powerdomain does not seem to work nicely anymore if you want to use other RTC functions afterwards. //For now I have disabled it in code, if you find WakeUp increases your powerconsumption, try enabling it again (code is still there, just commented) FunctionPointer WakeUp::callback; void WakeUp::set_ms(uint32_t ms) { if (!rtc_isenabled()) { //Make sure RTC is running rtc_init(); wait_us(250); //The f401 seems to want a delay after init } //PWR->CR |= PWR_CR_DBP; //Enable power domain RTC->WPR = 0xCA; //Disable RTC write protection RTC->WPR = 0x53; //Alarm must be disabled to change anything RTC->CR &= ~RTC_CR_ALRAE; while(!(RTC->ISR & RTC_ISR_ALRAWF)); if (ms == 0) { //Just disable alarm //PWR->CR &= ~PWR_CR_DBP; //Disable power domain RTC->WPR = 0xFF; //Enable RTC write protection return; } //RTC prescaler + calculate how many sub-seconds should be added uint32_t prescaler = (RTC->PRER & 0x7FFF) + 1; uint32_t subsecsadd = ((ms % 1000) * prescaler) / 1000; if ((ms < 1000) && (subsecsadd < 2)) subsecsadd = 2; //At least 2 subsecs delay to be sure interrupt is called __disable_irq(); //At this point we don't want IRQs anymore //Get current time uint32_t subsecs = RTC->SSR; time_t secs = rtc_read(); //Calculate alarm values //Subseconds is countdown, so substract the 'added' sub-seconds and prevent underflow if (subsecs < subsecsadd) { subsecs += prescaler; secs++; } subsecs -= subsecsadd; //Set seconds correctly secs += ms / 1000; struct tm *timeinfo = localtime(&secs); //Enable rising edge EXTI interrupt of the RTC EXTI->IMR |= EXTI_RTC_LINE; EXTI->EMR &= ~EXTI_RTC_LINE; EXTI->RTSR |= EXTI_RTC_LINE; EXTI->FTSR &= ~EXTI_RTC_LINE; //Calculate alarm register values uint32_t alarmreg = 0; alarmreg |= BYTE2BCD(timeinfo->tm_sec) << 0; alarmreg |= BYTE2BCD(timeinfo->tm_min) << 8; alarmreg |= BYTE2BCD(timeinfo->tm_hour) << 16; alarmreg |= BYTE2BCD(timeinfo->tm_mday) << 24; //Enable RTC interrupt RTC->ALRMAR = alarmreg; RTC->ALRMASSR = subsecs | RTC_ALRMASSR_MASKSS; //Mask no subseconds RTC->CR |= RTC_CR_ALRAE | RTC_CR_ALRAIE; //Enable Alarm RTC->WPR = 0xFF; //Enable RTC write protection //PWR->CR &= ~PWR_CR_DBP; //Disable power domain __enable_irq(); //Alarm is set, so irqs can be enabled again //Enable everything else NVIC_SetVector(RTC_IRQ, (uint32_t)WakeUp::irq_handler); NVIC_EnableIRQ(RTC_IRQ); } void WakeUp::irq_handler(void) { //Clear RTC + EXTI interrupt flags //PWR->CR |= PWR_CR_DBP; //Enable power domain RTC->ISR &= ~RTC_ISR_ALRAF; RTC->WPR = 0xCA; //Disable RTC write protection RTC->WPR = 0x53; RTC->CR &= ~RTC_CR_ALRAE; RTC->WPR = 0xFF; //Enable RTC write protection EXTI->PR = EXTI_RTC_LINE; //PWR->CR &= ~PWR_CR_DBP; //Disable power domain callback.call(); } void WakeUp::calibrate(void) { //RTC, we assume it is accurate enough without calibration } #endif