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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

#141

Post by vo2maxer »

ssl-3 wrote: post #137
antx wrote: post #131

Earlier quoted context omitted.

And we're also here to use double dashes, aren't we.

Yes, if we fucking choose to do that. We are.

Yes! The reflexive “must be LLM generated” is becoming ridiculous. Anything that includes proper punctuation and, god forbid, em dashes which I’ve used all my life must be suspect. The “it’s not x, it’s y” construction predates LLMs. I don’t recall ever sending a text without making sure it contained no errors, and yes, many have included infrequently used vocabulary.

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

#142

Post by stavros »

ssl-3 wrote: post #65
teraflop wrote: post #5

Cool project! The most interesting part, IMO, is the "SRAM with EEPROM backup" chip. It allows you to persistently save the clock hands' positions every time they're moved, without burning through the limited write endurance of a plain old EEPROM. And it costs less than $1 in single quantities. That's a useful product to know about.

That's really neat. TIL. So the way this works seems to be this: It's an SRAM and an EEPROM in one little package along with a controller that talks with each, with a little capacitor (this clock uses 4.7uf) placed nearby. The SRAM part does all of the normal SRAM stuff: It doesn't wear out from reading/writing, and as long as it has power it retains the data it holds. The EEPROM does all the normal EEPROM stuff: It…

Has anyone found the chip on AliExpress? I only get unrelated listings with that part number, but this is a pretty interesting chip I'd like to get a few of.

An alternative would be a supercapacitor and a voltage divider connected to the ADC pin of the microcontroller. When the 5V rail dies, the supercapacitor can hold 3.3V for a few seconds while you write everything to the EEPROM.

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

#143

Post by tanvach »

smithza wrote: post #124
tanvach wrote: post #115

Related - we have an atomic Seiko wall clock expecting to have the time automatically adjusted by the WWVB LF atomic clock broadcast. Turns out, the signal is very weak where we now live. Manually setting the time on these atomic clocks is a HUGE pain (beware!). 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 atomi…

I would be very careful of transmitting on the same frequency as WWVB. It is very likely illegal.

That’s a very good point but the transmission power is extremely weak and won’t propagate more than 1m.

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

#144

Post by jojobas »

stevenjgarner wrote: post #122

$3.88 ? Walmart.com uses dynamically variable pricing that includes geographic and user variance - my price is $5.92 https://www.walmart.com/ip/Mainstays-Basic-Indoor-8-78-Black...

An HN mention is surely grounds for a whopping $2.04 hike.

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

#145

Post by brokenmachine »

ChuckMcM wrote: post #75

Pretty awesome. The only thing I would change is to put a USB battery between the usb wall power and the D1 mini. That way for power outages of < a couple of days or so you're clock will be fine.

Why bother? Just get NTP time when the power comes back. It's syncing every 15 minutes anyway.

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

#146

Post by wileydragonfly »

smithza wrote: post #124
tanvach wrote: post #115

Related - we have an atomic Seiko wall clock expecting to have the time automatically adjusted by the WWVB LF atomic clock broadcast. Turns out, the signal is very weak where we now live. Manually setting the time on these atomic clocks is a HUGE pain (beware!). 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 atomi…

I would be very careful of transmitting on the same frequency as WWVB. It is very likely illegal.

Get out

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

#147

Post by dole »

smithza wrote: post #126
KaiserPro wrote: post #101

If your budget is a bit more, and you want to hear a massive clunk every 30 seconds rather than a soft tick and you want to drive 2' (60cm) hands, then you might want this: https://waitingtrain.blogspot.com/2015/05/a-large-gents-turr... The smaller ones look the same but are less beefy. I used one to make this clock: https://www.secretbatcave.co.uk/projects/electromechanical-c... Which instead of using a well discipl…

The DIY tuning fork clock is very cool. I am hard pressed to understand why accutron doesn't still make and sell tuning-fork watches. I really admire the creative use of resonance frequencies (not dissimilar to quartz watches but cool that you can really see the tuning fork for you watch as opposed to a diminutive quartz crystal).

They recently re-released the Accutron with actual tuning fork movements, but at $6k ofc you’re better off buying vintage:

https://www.hodinkee.com/articles/introducing-accutron-314

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

#148

Post by gruez »

stevenjgarner wrote: post #122

$3.88 ? Walmart.com uses dynamically variable pricing that includes geographic and user variance - my price is $5.92 https://www.walmart.com/ip/Mainstays-Basic-Indoor-8-78-Black...

https://en.wikipedia.org/wiki/Inflation

Git history shows it was published more than 2 years ago.

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

#149

Post by ssl-3 »

stavros wrote: post #138
ssl-3 wrote: post #72

Earlier quoted context omitted.

GPS isn't too hard, either. The receivers are inexpensive ($5-$10 for the kind of accuracy that's useful here) and it's not hard to parse the NMEA strings and PPS they output into a spooky-accurate internal clock. It only takes a few connections and an antenna to integrate GPS into an MCU like an ESP (or an SBC like a Raspberry Pi or a whatever). Like, really: The hardware is ridiculously easy. The only difficult par…

The actual difficult part is getting a GPS signal indoors with a cheap receiver, sadly.

I've had mixed luck.

My current house, with low-E windows, aluminum siding, and a metal roof? It passionately hates everything about GPS.

But in more-typical (stick-framed, asphalt shingled, vinyl-sided, US-ish) houses? I haven't had any trouble with my very inexpensive u-blox (or perhaps clone) GPS board, a presumed-decent GPS antenna that we were throwing away at work, and dainty little [IIRC] u.FL to SMA adapter to connect the antenna with. (I put this all together just to play with making a GPS-backed, low-stratum NTP server -- which was a much more-rewarding process than it had any right to be.)

It was bizarrely good, in fact: While it certainly saw more birds and presumably had better accuracy when sitting in a window, I had real trouble getting it to cease to operate. It seemed to lock on well-enough to provide time and PPS until I put the antenna into a windowless closet.

That said: The antenna that came with this cheap receiver was trash -- at best, 1/10. It was hard to make it work even outdoors on a clear day. I eventually got sick of looking at that part and binned it.

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

#150

Post by RupertSalt »

tanvach wrote: post #115

Related - we have an atomic Seiko wall clock expecting to have the time automatically adjusted by the WWVB LF atomic clock broadcast. Turns out, the signal is very weak where we now live. Manually setting the time on these atomic clocks is a HUGE pain (beware!). 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 atomi…

You do not have an atomic clock. Seiko does not manufacture “Atomic Clocks” for the $30 shelf in Target. You (and others here) don’t seem to know what an atomic clock is, or how it works, or what it costs!

Your Seiko is a radio clock. It’s probably got a crystal or some other normal timekeeping gadget, and the external WWV signal is decoded to properly set it.

“Atomic Clocks” are marketed to ignorant consumers who blithely use the term when the only external source is a radio station. The Stratum Zero clock may be atomic, but the caesium is not to be found on your nightstand.

No caesium atoms would be found in your Seiko, bro.

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