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] <mailto:[email protected]> http://www.fiwihex.nl <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/8DAFDBD9-346E-4162-985A-F14504E334FA%40fiwihex.nl.
