Syncing RTC To Network Time

[abilio]

We've just finished adding support for a NTP (SNTP) client. Syncing time will be as easy as:

import machine
rtc = machine.RTC()
rtc.ntp_sync("pool.ntp.org") # select an appropriate server

By default it will resync every hour, but you can change the period by passing it as a parameter: rtc.ntp_sync("pool.ntp.org", 1200) # do it every 20 minutes

This feature will probably be included in the next release. Hope you'll find it useful.

[thefebruaryman]

@abilio that's great news and much easier to use. Cheers for the good work!

[Knoahlr]

@abilio Will the method sync the RTC to local time or UTC ?

[abilio]

@Knoahlr, to UTC, but then you'll be able to set the time offset calling:

time.timezone(3600) # GMT +1 for the Netherlands

A call to time.localtime() will return the time using the provided offset. If you want the number of seconds since Epoch adjusted to the timezone, you can do something like:

time.time() + time.timezone()

Also, time.gmtime() will be included, working like time.localtime(), but without adjusting for the offset.

So far, this is what would be available in the release.

[Knoahlr]

@abilio Great, amazing feature.

[rdixey]

@abilio Apparently this is not yet implemented in 1.6.1.b1 ?

'1.6.1.b1'
>>> os.uname()
(sysname='LoPy', nodename='LoPy', release='1.6.1.b1', version='v1.8.6-450-g31ef5170 on 2017-02-15', machine='LoPy with ESP32', lorawan='1.0.0')
>>> import machine
>>> rtc = machine.RTC()
>>> rtc.ntp_sync("pool.ntp.org")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'RTC' object has no attribute 'ntp_sync'
>>> 
>>> import time
>>> time.timezone(3600)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'timezone'

[abilio]

@rdixey, you are totally right and I must personally apologize for it. We forgot to merge it with master just to realize it after making the release (yeah, it happened twice :( ) . I will work so is included in the next firmware release.

[rdixey]

@abilio These new rtc.ntp_sync() & time.timezone() functions work nicely with the 1.6.4.b1 update. They are very convenient!

I think there is a typo on the Utime doc page though. The first function listed there is utime.mktime([secs]), is this intended to be utime.gmtime()?

Thanks for the good work on this :)

[livius]

@rdixey said in Syncing RTC To Network Time:

mktime

It is standard in many languages - google for it ;-)

[santorcuato]

@rdixey said in Syncing RTC To Network Time:

@abilio These new rtc.ntp_sync() & time.timezone() functions work nicely with the 1.6.4.b1 update. They are very convenient!

I think there is a typo on the Utime doc page though. The first function listed there is utime.mktime([secs]), is this intended to be utime.gmtime()?

Thanks for the good work on this :)

Its not working for me :-(

Can you post a working example?

Thanks!

[rdixey]

@santorcuato I used it as a function in the boot.py of my LoPy. I had to set a delay to allow for the round trip to pool.ntp.org or else the function completed before ntp_sync and RTC remained = Unix Epoch . When I ping pool.ntp.org from my LAN the longest round trip was 630ms so I set sleep at 750ms. Less than that was too short.

def setRTCLocalTime():
    rtc = machine.RTC()
    rtc.ntp_sync("pool.ntp.org")
    utime.sleep_ms(750)
    print('\nRTC Set from NTP to UTC:', rtc.now())
    utime.timezone(-18000)
    print('Adjusted from UTC to EST timezone', utime.localtime(), '\n')

Connecting to a LoPy...
Connected
>>> 
PYB: soft reboot

RTC Set from NTP to UTC: (2017, 2, 26, 13, 18, 54, 225113, None)
Adjusted from UTC to EST timezone (2017, 2, 26, 8, 18, 54, 6, 57)

[rdixey]

@livius Excuse Me :) I already know what mktime() is. And I don't need anyone to give me instructions on using google to find info. I was pointing out a typo in the doc's.

https://docs.pycom.io/pycom_esp32/library/utime.html

mktime is the first function in the list and is described as 'Convert a time expressed in seconds since the Epoch.' I believe this is an error and should be gmtime().

mktime is listed again as the third functon and described correctly.

gmtime() is not in the list at all.

[livius]

@rdixey said in Syncing RTC To Network Time:

instructions

Without explanation that function is twice in doc - this was my first hint ;-)

[santorcuato]

@rdixey Ok, it seems interesting. Will try!

Thanks