1. include "select_program.h"

1. if PROGRAM == TEST_SLEEP

1. include "mbed.h"
2. include "rtc_api_hal.h"

enum WakeupType { WAKEUP_RESET, WAKEUP_TIMER, WAKEUP_PIN };

DigitalOut active_led(LED1, 0);

1. define WAKEUP_TIMEOUT_S 10 timeout to remain in standby mode before waking up through reset

bool standby_allowed = true; for locking out the standby if firmware update has started

static RTC_HandleTypeDef RtcHandle;

void rtc_set_wake_up_timer_s(uint32_t delta) { uint32_t clock = RTC_WAKEUPCLOCK_CK_SPRE_16BITS;

HAL_RTCEx_SetWakeUpTimer_IT will assert that delta is 0xFFFF at max if (delta > 0xFFFF) { delta -= 0x10000; clock = RTC_WAKEUPCLOCK_CK_SPRE_17BITS; }

RtcHandle.Instance = RTC;

HAL_StatusTypeDef status = HAL_RTCEx_SetWakeUpTimer_IT(&RtcHandle, delta, clock);

if (status != HAL_OK) { error("Set wake up timer failed: %d\n", status); } }

WakeupType get_wakeup_type() {

if(READ_BIT(RTC->ISR, RTC_ISR_WUTF)) return WAKEUP_TIMER;

this is set by timer too, but that's checked already above. if(READ_BIT(PWR->CSR, PWR_CSR_WUF)) return WAKEUP_PIN;

return WAKEUP_RESET; }

void standby() {

printf("Going to sleep!\n");

core_util_critical_section_enter();

Enable wakeup pin PA_0. HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);

Clear wakeup flag, just in case. SET_BIT(PWR->CR, PWR_CR_CWUF);

Enable wakeup timer. rtc_set_wake_up_timer_s(WAKEUP_TIMEOUT_S);

Enable debug interface working in standby. Causes power consumption to increase drastically while in standby. HAL_DBGMCU_EnableDBGStandbyMode();

HAL_PWR_EnterSTANDBYMode();

this should not happen... rtc_deactivate_wake_up_timer(); core_util_critical_section_exit();

printf("Got out of standby mode...\n")

something went wrong, let's reset NVIC_SystemReset(); }

int main() { printf("Hello world\n");

run_application() will first initialize the program and then call main_application() set_time(0);

active_led = 1; wait_ms(200); active_led = 0; wait_ms(200); active_led = 1;

standby(); }

1. endif PROGRAM == TEST_SLEEP