Hi Thanks for all the information. I have to read a lot. Till then I buy a cheap timer in the shop on the corner. Peter
Op dinsdag 20 april 2021 om 09:45:10 UTC+2 schreef Eur van Andel: > Hi Zet > > Olivier Seitz has said a lot of useful things about keeping time already. > I can add that some PIC18Fs have hardware real time clocks, some even with > support for a 32kHz watch crystal on special pins. This will be accurate to > minutes per year. > > Keeping time is of no use without syncing. That also holds for calendars. > Syncing is so important for agriculture that several ancient civilisations > spent insane amounts of work erecting huge stones to sync their calendars > with the orbit of the planet. > > If you want to sync your time, you need to connect to a network. I do this > in several ways: > > - with an RN171 wifi module, which is end-of-life, so not recommended > - with an ESP32 which is cheap but overkill > - with a SIM800L GSM module, which needs a SIM card > > SIM cards with data prices of €0.01/MB can be bought for €10 at keepgo.com > The SIM800L can be bought on AliExpress for €2 > I wrote a library for the SIM800, which I can add to jallib if you are > interested. The SIM800 is 2G only, so your country should still support > that. Europe does. > > The mobile network knows both the time, the time zone and the local DST. > (Daylight Savings Time) > > A low cost solution could be a local “Stonehenge” with a narrow slit and a > small solar cell that gives a good signal in direct sunlight. This would > require a fixed location for the hardware and an unobstructed view to (a > part of) the southern sky. You will also have to do some astronomical > calculations. The Druids in England did those 5000 years ago, without the > internet, so that won’t be too hard. > > You will be on solar time and syncing with a calendar will be hard, next > to impossible. So when the DST kicks in will be unknown. > > > On 19 Apr 2021, at 23:23:03, [email protected] <[email protected]> wrote: > > Does a library excist with timezone Amsterdam so the microprocessor can > use it to send an order to start or stop a device every day at the same > time? > > > --- > ir EE van Andel [email protected] http://www.fiwihex.nl > Fiwihex B.V. Wierdensestraat 74, NL7604BK Almelo, Netherlands > tel+31-653-286573 > > > > > -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/21a991c4-df5e-4db9-a69d-f58bfae43c94n%40googlegroups.com.
