ESP-12 RTC Accuracy

All ESP8266 boards running MicroPython.
Official boards are the Adafruit Huzzah and Feather boards.
Target audience: MicroPython users with an ESP8266 board.
devnull
Posts: 107
Joined: Sat Jan 07, 2017 1:52 am
Location: Singapore / Cornwall

ESP-12 RTC Accuracy

Postby devnull » Mon Mar 13, 2017 11:42 pm

I am using the in-built RTC on the 8266 to deepsleep for an hour, but it seems to be highly inaccurate, although it's repeatability seems to be OK.

Code: Select all

    secs = 3600
    rtc = mc.RTC()
    rtc.irq(trigger=rtc.ALARM0, wake=mc.DEEPSLEEP)
    rtc.alarm(rtc.ALARM0, (secs*1000))

In sleeping for 1 hour, it wakes up on average 108 seconds early, this seems to be a huge error and of course in 1 day this would be roughly 43 minutes a day assuming that the error is cumulative.

Can the clock be so inaccurate ??

Other than adding a multiplication factor into the sleep time code, is there away to calibrate / adjust the rtc ?

filipmar.mf
Posts: 3
Joined: Thu Jul 28, 2016 3:21 pm

Re: ESP-12 RTC Accuracy

Postby filipmar.mf » Tue Mar 14, 2017 8:54 am

I have the same observation. My "hour" has 57.5 min with amazing second precise repeatabilty with small minute variation time to time. Very strange behavior :?

User avatar
pythoncoder
Posts: 1564
Joined: Fri Jul 18, 2014 8:01 am

Re: ESP-12 RTC Accuracy

Postby pythoncoder » Tue Mar 14, 2017 10:27 am

Peter Hinch

devnull
Posts: 107
Joined: Sat Jan 07, 2017 1:52 am
Location: Singapore / Cornwall

Re: ESP-12 RTC Accuracy

Postby devnull » Tue Mar 14, 2017 1:56 pm

Peter - thanks, but after reading through that it appears that the issue was fixed ??

https://github.com/micropython/micropython/pull/2726

User avatar
pythoncoder
Posts: 1564
Joined: Fri Jul 18, 2014 8:01 am

Re: ESP-12 RTC Accuracy

Postby pythoncoder » Wed Mar 15, 2017 9:10 am

You haven't followed the chain to its end ;) See https://github.com/micropython/micropython/pull/2728. It has not yet been reviewed and accepted.
Peter Hinch

devnull
Posts: 107
Joined: Sat Jan 07, 2017 1:52 am
Location: Singapore / Cornwall

Re: ESP-12 RTC Accuracy

Postby devnull » Fri Mar 17, 2017 12:16 pm

Does not look like this is going to happen, 2728 has been closed / terminated, what a shame.

:(

User avatar
pythoncoder
Posts: 1564
Joined: Fri Jul 18, 2014 8:01 am

Re: ESP-12 RTC Accuracy

Postby pythoncoder » Fri Mar 17, 2017 3:55 pm

You can always fetch the PR and build it yourself. But it would be good to see it reviewed and merged.
Peter Hinch


Return to “ESP8266 boards”

Who is online

Users browsing this forum: No registered users and 2 guests