I'm testing 2 DS3231 at the moment. One gave 2-3 seconds off and the other gave 10 seconds off over a month. I also found and bought 2 rechargeable coin batteries, but one RTC circuit is still having 3 AAA batteries connected and came out to be better in that first test. Both have nice analogue clock graphics and numbers updating every second, so I'm happy with that whole thing. The further builds of what I thought about will take a bit more "work."
Thank you for sharing. That is really interesting. 10 Seconds a month was more than I was expecting. Does anyone else have stats on time slip on these devices?
I needed to make a synchronizer for my Self Winding Clock Company clocks. Basically it needs to wake up once per hour, assert a pin that will control the synchronizing signal to the SWCC clock. I need to have a run time of 6 months on a battery. I used a DS3231 for this. On startup it queries time via NTP, and sets the DS3231 time. I set the DS3231 alarm and make the pico go dormant, to wake on interrupt from the clock. When the alarm triggers the pico wakes, synchronizes the SWCC clock, resets its alarm, and goes dormant again. It will periodically query the time via NTP, once a week is enough for my purposes. It remains to be seen how long it lasts on a single battery charge, but signs are good I will exceed my 6-month goal.
The Lightning detector hardware is interesting. GPS gives the location of the sensor. GPS gives a once per second interupt. So you know very accurately how many microseconds the clock takes between each interupt Now measure when you receive the strike over the radio part, recoding the microsecond from the system clock Now you can divide to get a very accurate time to the microsecond. Send to the central server. ie. The GPS can be used to measure temperature changes in the clock, and that is used to compenstate
I use the internet in a "Pico 8" app and it gets hot to run on Raspberry Pi 3B/3B+/whatever. Now I want the Pico to take care of showing a nice clock and nothing got hot in my stress tests, but my breakthrough is MMBasic being simpler to code with all sorts of connections and text/graphics. I also want to "read" the sunshine (solar panel ideas), temperature and maybe log the data.
I'm testing 2 DS3231 at the moment. One gave 2-3 seconds off and the other gave 10 seconds off over a month. I also found and bought 2 rechargeable coin batteries, but one RTC circuit is still having 3 AAA batteries connected and came out to be better in that first test. Both have nice analogue clock graphics and numbers updating every second, so I'm happy with that whole thing. The further builds of what I thought about will take a bit more "work."
Thank you for sharing. That is really interesting. 10 Seconds a month was more than I was expecting. Does anyone else have stats on time slip on these devices?
I needed to make a synchronizer for my Self Winding Clock Company clocks. Basically it needs to wake up once per hour, assert a pin that will control the synchronizing signal to the SWCC clock. I need to have a run time of 6 months on a battery. I used a DS3231 for this. On startup it queries time via NTP, and sets the DS3231 time. I set the DS3231 alarm and make the pico go dormant, to wake on interrupt from the clock. When the alarm triggers the pico wakes, synchronizes the SWCC clock, resets its alarm, and goes dormant again. It will periodically query the time via NTP, once a week is enough for my purposes. It remains to be seen how long it lasts on a single battery charge, but signs are good I will exceed my 6-month goal.
That sounds excellent Ralph. Great project.
The Lightning detector hardware is interesting.
GPS gives the location of the sensor.
GPS gives a once per second interupt.
So you know very accurately how many microseconds the clock takes between each interupt
Now measure when you receive the strike over the radio part, recoding the microsecond from the system clock
Now you can divide to get a very accurate time to the microsecond.
Send to the central server.
ie. The GPS can be used to measure temperature changes in the clock, and that is used to compenstate
I use the internet in a "Pico 8" app and it gets hot to run on Raspberry Pi 3B/3B+/whatever. Now I want the Pico to take care of showing a nice clock and nothing got hot in my stress tests, but my breakthrough is MMBasic being simpler to code with all sorts of connections and text/graphics. I also want to "read" the sunshine (solar panel ideas), temperature and maybe log the data.
Sounds like a fun project.
Ok.
:-)