81–90 of 191 posts
I'm curious why we don't just use GPS's UTC time broadcast to set time? I understand that using GPS to track satellites and find location is power hungry, but I can't imagine that simply receiving a time and setting a clock is any more power hungry than this system.
Earlier quoted context omitted.
My professor is a materials/mechanical engineer and in contact with many auto companies. He told me of the following dialogue: Prof: Why did you stopped adding passenger side handles? How much one cost? CarGuy: Around €1.50 Prof: That's not much? CarGuy: A new car leaves the factory every 60 seconds. Prof: Oh. For the lazy, that's €2,160/Day, €64,800/Month, €777,600/year.
I guess, but still, these seemingly large numbers are still a minute percentage (e.g. probably 0.00001%) of overall costs/revenue that are relatively way, way more. I would understand manufacturing pain, and the ROI just doesn't justify it. But saying that it's solely to do with costs doesn't line up, IMO.
> I guess, but still, these seemingly large numbers are still a minute percentage (e.g. probably 0.00001%) of overall costs/revenue that are relatively way, way more.
Do you realise that your estimate, of €1.50 per car being 0.00001% of the costs, puts the manufacturing cost of a car at €15m?
Yes, as others have stated this is an old technology. I don't really understand why this is not more common in the modern day. it's not really that expensive to implement and they did it with analog chips back in the day... Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech. I don't understand. All you have to do is allow people to store an of…
I spend most of the time out of range, but the technology is simple and robust enough that you can use headphones or a phone speaker as a very, very short-range transmitter. You hardly need to sync every day, either. I've had most success with https://einoko.github.io/DCF77.js/
I have an alarm clock with this system (or I think it's this, it's from Oregon Scientific) and it has this "automatic clock sync" feature. I have it disabled. Once it was set to a random time, and I lost an important meeting because the alarm didn't ring at the correct time. The usual time doesn't deviate more than a second or so every few years, when I need to change the batteries and set it again so it's useless. T…
You press the receive button on the Casio.
> but the issue is that the messages are sent very sporadically so you either need to wait almost a full day for it to sync
The signal is constant. You probably had bad reception. In case of DCF77 it needs one minute to transmit "date + time + parity". I have seen my G-Shock syncing in under two minutes.
Yes, as others have stated this is an old technology. I don't really understand why this is not more common in the modern day. it's not really that expensive to implement and they did it with analog chips back in the day... Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech. I don't understand. All you have to do is allow people to store an of…
Note that an integer offset is insufficient. For example, Australian Central Standard time is +9:30 and Australian Central Western Standard Time is +8:45. I have a Seiko watch with a similar feature to this and I don't think it would work well in either of these timezones.
Yes, as others have stated this is an old technology. I don't really understand why this is not more common in the modern day. it's not really that expensive to implement and they did it with analog chips back in the day... Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech. I don't understand. All you have to do is allow people to store an of…
My Protrek basically doesn't sync if I'm at home, and as it tries to start sync after midnight the auto sync near-never works. I installed DCF77-emulator app on phone to get around it.
My radio-synced clock works fine but comes with big (BIC lighter size but double the thickness) external antenna.
Probably much worse in microwave that's somewhere inside the house and not near window
> All you have to do is allow people to store an offset for the time zone, and RTC issues are a thing of the past.
Just to clarify, we're talking about people who couldn't bother to put $0.2 capacitor to hold the RTC battery for the few hours the power is usually down, and you're expecting them to put whole antenna and radio in ?
Yeah, it isn't feature anybody will choose white goods for so it isn't in.
Yes, as others have stated this is an old technology. I don't really understand why this is not more common in the modern day. it's not really that expensive to implement and they did it with analog chips back in the day... Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech. I don't understand. All you have to do is allow people to store an of…
It does feel like something that’s easy to cut from a bill of materials though, nothing else in the microwave relies on the time being accurate. Probably not expensive to implement, but if you’re building a lot of them, I imagine the ~4cents per unit (maybe more, just guessing) adds up fast.
And they are too cheap to even put a capacitor in to cover for most short power failures
Related thread with local transmitters of time signal: https://news.ycombinator.com/item?id=27769403 https://github.com/hzeller/txtempus (A DCF77, WWVB, JJY and MSF clock LF-band signal transmitter using the Raspberry Pi) ios and mac app: https://forum.audiob.us/discussion/49109/pips-a-radio-time-s... (time sync over rf is super cool; I would be super interested if anyone has links to field surveys of time signal ava…
Thanks for those references! I wanted to see what an SDR radio time signal detector would look like, and looking for "DCF77 sdr python" pointed me in the right direction -> [0] and [1] A bit unrelated question: there are many web SDRs that let you listen to radio frequencies/stations such as [2]. Are there web / Emscripten SDR decoders that run in-browser? i.e. a full browser listening + decoding experience? For exam…