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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

#51

Post by mftrhu »

sowbug wrote: post #26
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.

I'm not sure if this is the same technology, but regardless it's also cool: https://www.adafruit.com/product/1897

Not quite - the chip the article refers to is the 47L04 [0], which is "just" NVSRAM built out of a RAM + EEPROM. I do agree on FeRAM being cool, though - I have a few I2C chips en route, and I can't wait to get my hands on them.

[0] https://www.microchip.com/en-us/product/47L04

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

#54

Post by jonathanlydall »

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…

Clocks which are designed to be able to auto set their time in the US will actually also do the auto setting at least as far away as Johannesburg, South Africa.

I know this because when my mother was visiting the US over a decade ago, she found a clock she felt was aesthetically perfect for her psychology practice room at her house.

Twice a year the clock changes its time to be 10 hours (or thereabouts) behind, no doubt due to daylight savings change over.

So she has to readjust the time whenever this happens which she says she doesn’t really mind.

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

#55

Post by montroser »

What I really want is one of these powered by gps. The time already comes for free in the signal, and from your location you can derive the time zone. That way DST is accounted for automatically, but you don't have to set up and rely on wifi. This would be truly zero-config and always correct.

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

#56

Post by hackingonempty »

lostlogin wrote: post #38
stavros wrote: post #32

Earlier quoted context omitted.

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.

Buy the premade thing and hack something new.

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

#58

Post by womod »

montroser wrote: post #55

What I really want is one of these powered by gps. The time already comes for free in the signal, and from your location you can derive the time zone. That way DST is accounted for automatically, but you don't have to set up and rely on wifi. This would be truly zero-config and always correct.

There's quite a few clocks available that get their time over the air from the NIST WWVB radio station[0]. They usually have a little switch on the back if your area does/doesn't observe daylight savings.

[0] - https://www.nist.gov/pml/time-and-frequency-division/time-di...

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

#59

Post by cyberax »

I was looking at the way they did the position sync. And they didn't :(

OK, here's how I'd do it: add small magnets at the bottom of the clock hands, and use the ESP's built-in Hall effect sensor to detect them. You can distinguish between hands using the magnetic field orientation.

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