Is it possible to wake from deepsleep using RTC alarm?

[bjg1968]

I want to be able to wake from deepsleep using the RTC alarm. I've tried the following, but still dead asleep. I can get the alarm event to occur, but as soon as I put it in deep sleep, it never occurs again. Am I doing something wrong or is this not possible?
Thanks.

`
#include <RTC.h>
#include <STM32L0.h>

void alarmMatch( void ) {
digitalWrite( 13, !digitalRead( 13 ) ); // toggle LED
STM32L0.deepsleep();
}

void setup() {
digitalWrite( 13, HIGH );
pinMode( 13, OUTPUT );

RTC.setTime(12, 52, 00);
RTC.setDate(24, 11, 21);

RTC.setAlarmTime( 0, 0, 20 );
RTC.enableAlarm( RTC.MATCH_SS );

RTC.attachInterrupt( alarmMatch ); // also tried RTC.attachInterruptWakeup( alarmMatch );
}

void loop() {
// do nothing here
}
`

[GrumpyOldPizza]

The STM32L0.deepsleep() needs to be in loop(). And in the alarm callback you need a STM32L0.wakeup().