https://en.wikipedia.org/wiki/Radio_clock
https://en.wikipedia.org/wiki/WWVB
I've had several that set automatically after plugging in, without the need for wifi.
It'd be cool if WiFi routers could broadcast the time unencrypted, for use by passive receivers, but that would get annoying if one near you is set wrong. Perhaps there could be a trusted source of signed timestamps, and a receiver just takes the maximum.
GPS transmit power is 44db with a 13 db antenna gain. I think. And -140 db sensitivity (typical) So close to 200db of link margin. And the transmitter isn't in clutter either.
Still leads to the same problem.
Also, as @rjsw mentions, accessing NTP doesn't help with setting alarms. Just setting the clock time - assuming your timezone is set correctly by the device.
It can't possibly be expensive. Pocket calculators cost $5.
The best features are the following: It has a battery-backed time-keeping chip which means it has never needed to have the time reset due to any loss of power to its main power supply. It has a piezo alarm that will sound if the main power is out and the alarm is on and triggered.
It also has a slide switch labeled "DST -on DST -off" so in theory I would never have to +/- the time EVER once it was on the right time zone.
I found it in a outlet-style store when I was looking for a WWV clock and this clock answers all my clock needs without needing WiFi, Bluetooth, any other antenna (for AM/FM radio it might be using the power cord, but I don't need that). It doesn't need to be told a password and I don't need to set up an account.
I think it was marked down to $10 when I bought it.
It's cruel to describe such a thing without providing a link or at least a brand name/model number.
Yeah, that's why I don't own one. Since I'm not ready to invest in one with a bell/gong, at least my smartphone has a proper speaker. Piezos are good for smoke alarms and such, but waking up to one is awful.
Also bought at a physical store, though I don't remember how much it cost. I think I last used it around 2011, though I do still have it. Wonder if it still works...
/s
1. Set up a Siri Shortcut "when alarm goes off, play Spotify". Haven't done it, but having been knee-deep in Shortcuts this weekend, I'm confident that it is possible, and (on latest iOS) not difficult even for a Shortcuts n00b. (For Android, I know Tasker can do this.)
2. Fiddle with buggy and not-maintained-as-soon-as-it-shipped application to set alarm clock. Application must run on a computer that, coincidentally, can serve as a full-function WiFi-enabled alarm clock and can set its own damned time.
Also, alarm clocks tell the time with a quick glance. I like to know what time it is in the middle of the night, just by looking at a clock.
You might simply like the look of the alarm clock more than your phone, but still want to be able to use some of those smart features.
My dumb alarm clock is the last and only thing I possess that requires I set the time manually. And it drifts. Even my wristwatch autosynchronizes every night to the time server signal sent over RF from Denver. I've seriously considered modding the alarm clock to autosync that way as well.
My alarm clock is a sunrise alarm clock with a 100W bulb. Can't quite replace with a cell phone. But maybe with smart bulbs. Hmm, I might have to rethink this whole thing.
Who needs radio sync signals, NTP servers, or a freaking GPS module (lol) when we have this great hardwired 60 Hz frequency reference which is measured and adjusted for long-term stability...
https://en.wikipedia.org/wiki/Utility_frequency#Long-term_st...
> Today, AC-power network operators regulate the daily average frequency so that clocks stay within a few seconds of correct time. In practice the nominal frequency is raised or lowered by a specific percentage to maintain synchronization. Over the course of a day, the average frequency is maintained at the nominal value within a few hundred parts per million.[19] In the synchronous grid of Continental Europe, the deviation between network phase time and UTC (based on International Atomic Time) is calculated at 08:00 each day in a control center in Switzerland. The target frequency is then adjusted by up to ±0.01 Hz (±0.02%) from 50 Hz as needed, to ensure a long-term frequency average of exactly 50 Hz × 60 s/min × 60 min/h × 24 h/d = 4320000 cycles per day.[20] In North America, whenever the error exceeds 10 seconds for the east, 3 seconds for Texas, or 2 seconds for the west, a correction of ±0.02 Hz (0.033%) is applied. Time error corrections start and end either on the hour or on the half-hour.[21][22] Efforts to remove the TEC in North America are described at electric clock.
The reason these clocks are so bad is that they use bad RTC units to save a couple dollars. A bad RTC can be had for pennies. A good one (like a DS3231) is $4! Thus, we are all stuck with bad clocks; AC powered or otherwise.
GPS/NTP/WWVB exist to get the time right initially. A clock will be wrong if you set it to the wrong time, even if you have a perfect frequency reference.
That might be a fun project, but I'd worry a bit about the future of RF time sync. The program was almost shut down this year but was funded after a small fight. I wouldn't be surprised if the funding doesn't come through the next round.
That being said, NTP only returns GMT. You still have to hardcode your timezone and whether DST is active or not, right?
https://github.com/heeen/vfd-clock
looking back at the code, doesn't seem like I handled DST though. I would probably use something like wifimanager now to allow dynamically configuring wifi and other things
Is clicking a couple physical buttons on an actual device such a strain?
If you're frequently setting multiple alarms, as many people do on their phones for various reasons, does it benefit you to use this rather than just using your phone?