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Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

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Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#31

Post by drivers99 »

orev wrote: post #12
kotaKat wrote: post #2

Of note, having recently shopped at Walmart for a self-setting alarm clock (what I once knew to be “atomic”): Apparently the entity today known as Sharp sells “AccuSet(tm)” branded clocks that “automatically set time”… but they’re just factory pre-set with a button cell and they include a slider on the bottom to set a timezone offset (only for US timezones). If you’re lucky, the clock’s battery is still good and the…

These clocks are irritating because they show up in the results when searching for “radio atomic clock” and similar, and it can be very hard to figure out if they actually use the WWVB radio signal. I’ve concluded that none of them do, because WWVB is only reliable in (most parts) of the US, and companies only want to make things that appeal to a global audience now. La Crosse seems to be the only one that makes them…

There are actually other time signals around the world.

I had a Casio wave ceptor (one with analog hands which it doesn't look like they sell anymore; I should have kept it). Anyway, looking at a model that's currently available (WV-200R, but there are 2 other models available), its manual says it gets signals from "Germany (Mainflingen), England (Anthorn), United States (Fort Collins), [and] Japan."

I was curious so I looked those up:

Mainflingen DCF77 77.5 kHz

Anthorn 60 kHz

Fort Collins WWVB 60 kHz

Japan looks like they have Mount Otakayoda 40 kHz, and Mount Hagane 60 kHz.

There are also some other countries that have time broadcasts (e.g. France. Anywhere else?) but not that that watch uses.

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#32

Post by stavros »

lostlogin wrote: post #20
riskable wrote: post #13

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…

Undermining the spirit of HN: By the time you’ve spent a few hours hacking away and bought any parts, that price is probably not too bad.

That's assuming you don't like hacking and would pay to not have to do it, which is generally not the case around here.

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#33

Post by ElevenLathe »

riskable wrote: post #13

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.

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#34

Post by russdill »

sowbug wrote: post #15
DesiLurker wrote: post #3

makes me wonder what if I just wanted to sync with nfc every once in a while. wifi seems overkill for this. maybe it could be done much cheaper with nfc sync witha phone twice a year?

We've been shopping for a simple bathroom clock to replace our final Amazon Echo and leave that increasingly dystopian ecosystem. There are some models that use Bluetooth on your phone to sync the time. I could imagine BLE being a good low-power and relatively stateless solution. But given our goals, we're not going to install an app on a phone just to maintain a wall clock. (I'd be fine if Android provided BLE time…

Home assistant has pretty good BLE capabilities. But honestly, as has already been pointed out wifi is already really cheap.

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#36

Post by freedomben »

Hell yeah, this is some badass hackery, and the type of stuff I love seeing on HN. In the last decade or so as more and more stuff becomes locked down and hacker unfriendly, I've found myself longing for simple things I can hack on. If I ever get to a point where I don't have to work for a living, one of the things I'd like to do is build everything from little gadgets up to major appliances that are simple, reliable, and hackable for people who want to. It pains me that my appliances have full computers driving them but I can't get access to them. Kudos for this awesome work and phenomenal write-up!

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#37

Post by ortichic »

Sorry if this is a dumb question, but do you guys not have radio controlled clocks outside of Europe? If I got it right, the only purpose of this project is to always display the correct time. Radio controlled clocks do exactly that. They are cheaper than the one ESP board, and run years on a single AA battery. No WiFi, tinkering, setup, or cables necessary

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#38

Post by lostlogin »

stavros wrote: post #32
lostlogin wrote: post #20

Earlier quoted context omitted.

Undermining the spirit of HN: By the time you’ve spent a few hours hacking away and bought any parts, that price is probably not too bad.

That's assuming you don't like hacking and would pay to not have to do it, which is generally not the case around here.

I’m think you can go further than that.

Days spent modifying cheap electronics is absolutely encouraged.

Re: Converting a $3.88 analog clock from Walmart into a ESP8266-based Wi-Fi clock

#40

Post by qwertygnu »

ortichic wrote: post #37

Sorry if this is a dumb question, but do you guys not have radio controlled clocks outside of Europe? If I got it right, the only purpose of this project is to always display the correct time. Radio controlled clocks do exactly that. They are cheaper than the one ESP board, and run years on a single AA battery. No WiFi, tinkering, setup, or cables necessary

Googled "radio controlled clock" and seeing results from $20-$200, lots of inconsistency in what the product is.
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