ds3231_alarm.py

# ds3231 alarn
# Alarm test using  a modify version of Peter Hinch ds3231 RTC library
# Author: Daniel Perron
# date: August 14, 2022
# Copyright Daniel Perron Released under the MIT license

import sys
from machine import Pin, I2C
import utime
from ds3231_port import DS3231

#utime index dictionary
time_idx={'year':0,'month':1,'mday':2,'hour':3,
          'minute':4,'second':5,'weekday':6,'yearday':7}

# set I2C
scl_pin = Pin(17, pull=Pin.PULL_UP, mode=Pin.OPEN_DRAIN)
sda_pin = Pin(16, pull=Pin.PULL_UP, mode=Pin.OPEN_DRAIN)
i2c = I2C(0, scl=scl_pin, sda=sda_pin)

#set input pin to read ds3131 interrupt
ds3231_int_pin = Pin(14,pull=Pin.PULL_UP, mode=Pin.IN)

# create ds3231  object
ds3231 = DS3231(i2c)

#disable alarm
ds3231.enable_alarm(1,False)
ds3231.enable_alarm(2,False)


#get ds3231 time and set rtc


# print RTC time (RTC was set)
print('DS3231 time:', ds3231.get_time(set_rtc=True))
print('RTC time:   ', utime.localtime())
print('')
print('')

# set alarm1 for 10 second
now = utime.localtime()
alarm1 = utime.localtime(utime.mktime(now)+5)
print("set alarm1 for 5 sec")
ds3231.set_alarm(alarm_id=1,alarm_time=alarm1,match=ds3231.ALARM_HMS_MATCH)
print("now ",now)
print("target",alarm1)
print("======== step 1 sec")

while True:
    print(utime.localtime())
    if ds3231_int_pin.value()==0:
        break
    utime.sleep(1)

print("done")
print("========")
#disable alarm1
ds3231.enable_alarm(1,False)
print('')
print("set alarm2 for next min start")
# wait to get at least 2 seconds ti prevent false int
while True:
    now = utime.localtime()
    alarm2 = utime.localtime(utime.mktime(now)+60)
    #reset second
    alarm2 =  (alarm2[0], alarm2[1], alarm2[2], alarm2[3], alarm2[4],  0 , alarm2[6], alarm2[7])
    if (utime.mktime(alarm2) - utime.mktime(now)) > 2:
        break;

#alarm2 doesnt have second
ds3231.set_alarm(alarm_id=2,alarm_time=alarm2)
print("now ",now)
print("target",alarm2)
print("======== step 5 sec")
while True:
    if (utime.localtime()[5]%5) == 0:
        print(utime.localtime())
    if ds3231_int_pin.value()==0:
        break
    utime.sleep(1)
print("done")
print("========")
ds3231.enable_alarm(2,False)