Time Station Emulator | Hacker News Reader

Time Station Emulator

github.com

241 pointsFriedPickles59 comments

You can apparently lock shopping trolleys using the same kind of principle - https://www.tmplab.org/2008/06/18/consumer-b-gone/

And https://www.youtube.com/watch?v=LmSyb0kBvGE

He kind of buried the lede, there's another MP3 to unlock them.

I once programmed my TI-84 calculator to do exactly this! The only missing thing was a circuit to convert the audio jack output voltage into the needed form for an antenna. I had the CS know-how but no EE know-how, so I never got it to work. It was fun to dream about confusing my high school's clocks though. (Sadly, the other obstacle was that the clocks only listened for the signal overnight, which improved their chances of detecting the weak broadcast out of far-away Colorado.)

> audio jack

That's a serial port, except when you're playing Bad Apple

I didn't know that about the overnight; that's neat. I'm often in my garage before work, and I always assumed the 5am reset time was just because only weirdos are noticing a clock whir its arms around then.

I live just beyond the fringe zone for reception of WWVB on my Casio Waveceptor. Depending on solar conditions, and how I leave the watch overnight (south-east facing window with space to a metal window frame for a coupling effect), I can get it to sync once in a while.

“One of the higher-frequency harmonics inevitably created by any real-world DAC during playback will then be the original fundamental, which should leak to the environment as a short-range radio transmission via the ad-hoc antenna formed by the physical wires and circuit traces in the audio output path.”

Sometimes I think I’m a smart guy…and then I read of people doing shit like this.

Came here to say this, I literally can't believe this works.

It's like a couple of years ago where someone showed a proof of concept of turning a HDD into a microphone

… and I thought the Scanjet 5p “Ode to Joy” easter egg was incredible.

It turns out those shopping car wheel locks use the same kind of low-frequency RF that can leak from your phone speaker. Someone made an app that allows you to lock or unlock certain shopping carts.

Van Eck Phreaking dates back to 1982, which used CRTs, and if you're aware of that, it's not an insurmountably huge logical leap to realize that modern hardware can be exploited the same way (thanks to greater sensitivity in receiving devices).

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

I first learned about this while reading Cryptonomicon. It seemed too fantastical to be a real thing.

Pretty sure it was in Snow Crash

No, check out https://en.wikipedia.org/wiki/Cryptonomicon#Technical_conten...

It was in a passage where some secondary character was in a prison cell and managed to spy on the screen across the wall using the technique.

Reminds me of the theremin. Turning an interference into something useful (or beautiful)

THIS is what you call hacking

A shame this hasn't shot to number 1 on HN and stayed there. At least it's getting reasonable upvotes.

This is a truly fantastic piece of hacking, going by the original meaning of the word as used within the dawn of the computer era.

Me, every day on HN, feeling that imposter syndrome.

This could be really useful in the future. NIST has been talking about retiring its radio-syncing signal, as there are better modern alternatives with satellites, the Internet, etc. But last time they suggested this there was an outcry, not just from the public with old radio-synced clocks and watches, but also industry with legacy equipment using it. This provides a solution.

Satellite-based time signals also seem easier to spoof, given the inherent power constraints of the transmitters.

That said, newer ones can use authentication, which (together with a reasonably accurate local oscillator) can prevent at least trivial spoofing.

The most common satellite-based time signal today is GPS and global navigation system signals are possible to spoof, but it is harder than "trivial" at least.

Shame there's no video demonstrating it working. It's a fun idea but without a demo, I'm left wondering about the efficacy.

I wasn't able to get this to work on a Pixel 8 in Chrome/Firefox on a JP region clock

I used a different app on a Pixel 8 Pro and it worked well. It uses the same principle.

https://play.google.com/store/search?q=junghans&c=apps

I can't tell if I'm fooling myself or if this actually (partially) worked. Is it possible for only the hour and seconds to sync if the signal isn't perfectly received? How long is it supposed to take to sync the time? Is it possible that this can confuse clocks that get a strong enough real signal while the phone is running this nearby?

I just tried it on a clock that has only ever successfully synced once many years ago, and it's still in the same bad location that never seemed to get a strong enough signal.

Its crappy little LCD animation did indeed seem to dance in sync with when I would turn the signal on and off on my phone. It took a few minutes of trying but then suddenly the hour and seconds updated to the exact time. Had to set the minutes manually :/

It takes a whole minute for the entire data frame to be transmitted. While 1 bps is great for propagation, WWVB (and it's kin) is a really weak signal to pickup using the tiny antennas these kinds of clocks have. There's a relationship between received power, modulation type, data rate, error correction, and error rate so changing one will change others. Thus it can sometimes take at least several minutes for all of the timing data to be gathered as there is no error correction included in the data frame. Also the HF spectrum is incredibly noisy as switch-mode power supplies (pretty much in everything these days) produce a ton of interference so taking a battery powered clock outside can help greatly.

WWVB clocks are great but aren't so good these days. NTP is pretty much as good as anyone will ever need in their home but this has the downside of usually requiring internet access. GPS clocks have been the standard for 30+ years for anyone needing precision timing.

I have a big old analog radio-controlled clock in my classroom, and it's always about 4 minutes fast, which would drive me nuts except most of my students can't read analog time so they're never confused by it.

Regardless, I'm excited to try this out next time I'm in the classroom. I'm a little confused by time zones, however. My clock has no controls on the back whatsoever (at least that I can find, I haven't opened it up), so I assume it doesn't know what time zone I'm in.

So do I need to set the time zone on the station emulator? There's an "offset" setting, but it says it's only for correcting "minor errors."

If you are in the USA, your clock must have a time zone control (or be fixed to one time zone), because the WWVB signal broadcasts UTC.

Ah, hunting the serial number led me to discover that the clock is part of a centrally-synchronized wireless clock system. The company is discontinued, so who knows how old these are. So I'm going to hunt down a wireless transmitter somewhere in the building that is setting my clock four minutes fast... Oh well, I don't get to try out OP's cool tech!

This is pretty darn cool, but I have to say I was somewhat let down by the WWVB signal. I was expecting the entire audible range instead of simply the extracted data. That being said, that's also really darn cool.

I find the WWV/WWVB droning soothing somehow.

Err… WWVB has no audio range. The carrier frequency is only 60 kHz. It’s effectively a CW signal since the amplitude is only modulated once per second.

There is an audible setting in the app that shifts the signal down to human range.

> WWVB has no audio range

I got my WWVB and WWVH confused!

There's a reasonable emulator here: https://wwv.mcodes.org/

Unfortunately it doesn't let you play both at the same time, which is what you need for the full experience.

You can always call WWV! https://en.wikipedia.org/wiki/WWV_(radio_station)#Telephone_...

There’s a voice mode station that mixes time signals and voice messages together during broadcast. This station also includes GPS errata from time to time, which in my head canon, are received by solo sailors crossing the Atlantic.

I thought this was Boulder, but I assume not?

That's WWV, also in Fort Collins, but on a very different frequency in the shortwave band.

Here's an emulation of WWV I did with a transmit capable SDR.

https://www.youtube.com/watch?v=9LsJn0CyyZI

> I find the WWV/WWVB droning soothing somehow.

Me too. I had a Hallicrafter S-38 as a kid and used fall asleep by WWV & CHU. It felt like a private space that only nerds could find.

check out this guy, doing something similar sending Lora packets without a radio - https://youtu.be/eIdHBDSQHyw?si=MGteEp72Mz52qNqu

"This video explores LoRaWAN communication using a microcontroller without a dedicated radio chip. CNLohr demonstrates techniques to transmit LoRa packets over surprisingly long distances, pushing the limits of inexpensive hardware. The project involves creative software and hardware interaction to generate signals at unexpected frequencies."

It says it doesn't work on iOS Safari, but iOS users can get the "Clock Wave" app from the app store which does the same thing. (And allows fun time zone tricks with clocks from other countries.)

thank you for this reply! i've got 6x CASIO watches and have struggled to the time on them synced for over a decade. a quick [small] purchase later and every single one of my CASIOs are synced. i'm so happy. its the little things that matter. thanks again.

I'm surprised and impressed that this works. I would've guessed phones have enough RF shielding and low-pass filters in the audio path to prevent this.

Very impressive, I just tried it, the first time it worked but synced the wrong time, despite the device time is correct, the browser (preview part) had the wrong time however. I tried to offset the time and sync it again, the watch is detecting the signal but no sync.

Nonetheless, pretty amazing!

Just an update on this, it turned out my watch also adds an offset hence the wrong time, just remove the site offset and it works flawlessly!

I remember years ago I bought a clock that advertised it set itself using the atomic clock broadcast.

Which it did. The very first time it was plugged in, and then never again after. The clock also kept horrible time, it lost a couple minutes every month. Truly an astonishing piece of wtf engineering.

What's weird is it seems like for a long time now I haven't seen "self setting" clocks on retail shelves in a while at big box stores. Everyone went back to just manual timekeeping and I haven't seen a self-setter in a hot minute.

I recently bought 2 of them.

You have to specifically look for the feature. Most do not have it.

Just to revisit this - I actually bought an "automatic setting" clock now that I saw one at Walmart.

Unfortunately, Sharp is lying. "Accu-Set(tm)" is them factory-programming the clock IC and just shipping a button cell in the box and hoping it holds time. My clock was 5 minutes behind and I have to manually set it. No RDS, no radiotime, nothing.

Oi... guess I have to be even more specific in my product hunt.

thats a new one had not see that before.

One of them I bought the feature is not clear if it is 'on/off'. It is a weird tower icon with another weird icon under it. One of them means turn it on. The other means turn it off but leave it on (why). So to make it work you have to have the little tower but the one under it on too. So two toggles to make it work. The other one I bought the thing was supposed to set itself on first power on. Yet to see that work right. Probably have to bring it outside to make work.

I really wish microwaves and ovens came with radio-controlled clocks.

While the mains frequency is usually a great (long-term) stable frequency source, the bigger problem is that all microwaves I know lack a backup battery and require re-setting after unplugging them.

And the 2024 lateral thinking award goes to...

Ha, there's one radio clock in my house that I still keep going for sentimental reasons... it's had a rough time setting itself for a few years, likely due to its placement in the house.

I'll have to test this out sometime, what a fun idea!

I’ll have to see if this can work with a multi band 6 gshock, I assume it’s similar to a standard atomic clock?

I was like is the clock transmission only 50khz and then wow it relies on harmonics.

What? Wow

I read the title as 'Train Station Emulator'. :)

This certainly looks impressive but it’s a bit misleading to say it works on “almost any phone” when it doesn’t work on iPhone (which only allows mobile Safari)

Whenever I see things like this, my first thought is that somebody is going to write something to mess up nearby atomic clocks, just because they can, then I think- why, why did you do this?

Then someone will respond: you’re just catatrophising- anyone could’ve done this years before now, and I’ll say no, because it wasn’t up on frontpage HN there with code so that anyone would think of it. Then they’ll say, well why did you tell everyone that idea then! It’s your fault! Then I’ll say that someone would’ve done it if it weren’t me. Then I’ll go have a beer.

Are you sure the beer didn't come first?

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