111–120 of 202 posts
Earlier quoted context omitted.
"Hey, someone on the Internet used decent diction! Obviously, this means I must accuse them of being a bot!" (Hey Dang. Can we get a ban button? There's a few people here that are impossible to conduct rational discourse with. My sanity would improve if they were simply gone from my view.)
You've edited the response since you posted it. I think there's a difference between diction and the standard output of ChatGPT et al.
I want to see someone convert one of those cheap projection clocks like this: https://www.homedepot.com/p/La-Crosse-Technology-5-in-Color-... The red projection is just the right brightness (at night) but it sucks that it's not wifi-enabled so you can't just get it to NTP sync (or hook up a GPS receiver). The projector part of the clock is a separate device that's attached to it via a ribbon cable. I would reverse en…
The one you linked claims to have "Atomic Time" which usually means syncing by radio from WWV/WWVB. I have several cheap wallclocks like this (though none with a projector) and they are always accurate with no noticeable drift AFAICT. Have you tried that particular one and found its accuracy wanting? I think, in principle at least, there should be less jitter in this method than using NTP over a computer network.
There are UK and Japan clocks that work similarly, but use national time sources. There are G-Shock watches which synchronize from multiple sources. While running on solar power. Those keep accurate time with no maintenance. That's an impressive achievement.
I'm mostly interested in what goes wrong. I've made enough of these projects to know that ~75% need modifications that were not anticipated. For instance, I made a freezer temp sensor to php email for cases where the freezer stops working... but when I opened the freezer, it would send an email. I needed to sample for 30 minutes or something. Maybe this was simple and you will be part of the 25% that work perfect and…
Earlier quoted context omitted.
The one you linked claims to have "Atomic Time" which usually means syncing by radio from WWV/WWVB. I have several cheap wallclocks like this (though none with a projector) and they are always accurate with no noticeable drift AFAICT. Have you tried that particular one and found its accuracy wanting? I think, in principle at least, there should be less jitter in this method than using NTP over a computer network.
Right. WWVB clocks running off the 60KHz pretty much solve the clock problem in the US. All my clocks at home are basic LaCrosse analog clocks. They have the internal sensors needed to tell when each hand is straight up, so they can set themselves without user input. On power up, they step until the hands are straight up, then sync when they get an update. You have to set the time zone with a switch when installing.…
YMMV depending upon location. I've never gotten a WWVB clock to work in North Carolina. On the East Coast, the signal maybe sorta works for a few hours overnight:
https://tf.nist.gov/tf-cgi/wwvbmonitor_e.cgi
T̶h̶e̶y̶ ̶a̶l̶s̶o̶ ̶d̶o̶n̶'̶t̶ ̶t̶r̶a̶n̶s̶i̶t̶i̶o̶n̶ ̶D̶S̶T̶ ̶a̶u̶t̶o̶m̶a̶t̶i̶c̶a̶l̶l̶y̶,̶ ̶s̶o̶ ̶y̶o̶u̶'̶r̶e̶ ̶p̶u̶l̶l̶i̶n̶g̶ ̶t̶h̶e̶m̶ ̶o̶f̶f̶ ̶t̶h̶e̶ ̶w̶a̶l̶l̶ ̶t̶w̶i̶c̶e̶ ̶a̶ ̶y̶e̶a̶r̶ ̶u̶n̶l̶e̶s̶s̶ ̶y̶o̶u̶'̶r̶e̶ ̶i̶n̶ ̶o̶n̶e̶ ̶o̶f̶ ̶t̶h̶e̶ ̶r̶a̶r̶e̶ ̶U̶S̶ ̶l̶o̶c̶a̶t̶i̶o̶n̶s̶ ̶t̶h̶a̶t̶ ̶d̶o̶n̶'̶t̶ ̶a̶d̶h̶e̶r̶e̶ ̶t̶o̶ ̶t̶h̶e̶ ̶D̶S̶T̶ ̶s̶i̶l̶l̶i̶n̶e̶s̶s̶. Edit: My bad, they can switch in/out of DST automatically, at least when they can work at all.
Turns out it's possible to emulate the atomic clock signal quite easily with a Raspberry Pi, or in my case I put together Arduino code that can emulate atomic clock broadcasts from around the world using an ESP32 module using NTP servers: https://github.com/tanvach/clocksync
The history of these atomic clock broadcast signals and their differences in different countries is quite fascinating.
On this topic. Do WiFi signals contain time (unencrypted)? If so why does my oven not pull time from the air and needs adjustment every 2 months? If not, why are APs not defacto time beacons for all sorts of non-smart appliances (and clocks)?
The advantage is that smart devices might have Matter support already. People with Matter devices will have border routers, which are perfect place for running NTP and broadcasting time.
Earlier quoted context omitted.
Right. WWVB clocks running off the 60KHz pretty much solve the clock problem in the US. All my clocks at home are basic LaCrosse analog clocks. They have the internal sensors needed to tell when each hand is straight up, so they can set themselves without user input. On power up, they step until the hands are straight up, then sync when they get an update. You have to set the time zone with a switch when installing.…
> WWVB clocks running off the 60KHz pretty much solve the clock problem in the US. YMMV depending upon location. I've never gotten a WWVB clock to work in North Carolina. On the East Coast, the signal maybe sorta works for a few hours overnight: https://tf.nist.gov/tf-cgi/wwvbmonitor_e.cgi T̶h̶e̶y̶ ̶a̶l̶s̶o̶ ̶d̶o̶n̶'̶t̶ ̶t̶r̶a̶n̶s̶i̶t̶i̶o̶n̶ ̶D̶S̶T̶ ̶a̶u̶t̶o̶m̶a̶t̶i̶c̶a̶l̶l̶y̶,̶ ̶s̶o̶ ̶y̶o̶u̶'̶r̶e̶ ̶p̶u̶l̶l̶i̶n̶g̶ ̶t…
> The DST status bits indicate United States daylight saving time rules.
Earlier quoted context omitted.
> WWVB clocks running off the 60KHz pretty much solve the clock problem in the US. YMMV depending upon location. I've never gotten a WWVB clock to work in North Carolina. On the East Coast, the signal maybe sorta works for a few hours overnight: https://tf.nist.gov/tf-cgi/wwvbmonitor_e.cgi T̶h̶e̶y̶ ̶a̶l̶s̶o̶ ̶d̶o̶n̶'̶t̶ ̶t̶r̶a̶n̶s̶i̶t̶i̶o̶n̶ ̶D̶S̶T̶ ̶a̶u̶t̶o̶m̶a̶t̶i̶c̶a̶l̶l̶y̶,̶ ̶s̶o̶ ̶y̶o̶u̶'̶r̶e̶ ̶p̶u̶l̶l̶i̶n̶g̶ ̶t…
I'm fairly certain the radio time signal has a mechanism to convey daylight savings, I've had alarm clocks that managed DST without any input. > The DST status bits indicate United States daylight saving time rules. https://en.wikipedia.org/wiki/WWVB
I want to see someone convert one of those cheap projection clocks like this: https://www.homedepot.com/p/La-Crosse-Technology-5-in-Color-... The red projection is just the right brightness (at night) but it sucks that it's not wifi-enabled so you can't just get it to NTP sync (or hook up a GPS receiver). The projector part of the clock is a separate device that's attached to it via a ribbon cable. I would reverse en…
Now if only I could turn off the clocks on my oven and microwave...