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Casio G-Shock time sync radio

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Re: Casio G-Shock time sync radio

#121

Post by defrost »

Qqqwxs wrote: post #120
friend_and_foe wrote: post #80

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.

GPS determines a solution for position and time simultaneously. It requires 4 satellites to solve for 4 unknowns (X, Y, Z, t). If you know your position you can solve for time using only 1 satellite, but a watch is always moving so it's position won't be known.

You might want to rethink that.

There's no need to 'solve' for time - it's included in the raw data packet from any single satellite.

As any 'solution' carries an inherent error margin, the desire for an excess of sats doesn't stem from solving for time but the reduction of error.

Re: Casio G-Shock time sync radio

#122

Post by Qqqwxs »

defrost wrote: post #121
Qqqwxs wrote: post #120

Earlier quoted context omitted.

GPS determines a solution for position and time simultaneously. It requires 4 satellites to solve for 4 unknowns (X, Y, Z, t). If you know your position you can solve for time using only 1 satellite, but a watch is always moving so it's position won't be known.

You might want to rethink that. There's no need to 'solve' for time - it's included in the raw data packet from any single satellite. As any 'solution' carries an inherent error margin, the desire for an excess of sats doesn't stem from solving for time but the reduction of error.

More specifically, you need to solve for the receiver clock bias.

https://www.e-education.psu.edu/geog862/node/1724

Edit: I would welcome corrections though if I am misunderstanding. Perhaps if you're not interested in precise timing you can read the satellite time from the broadcast signal?

Edit 2: OK, I think I understand your point now. The satellites broadcast their timestamps directly. To find a precise position / time you need to find a correction to the receiver clock. But if you don't need a very precise time, you can just use the satellite timestamp.

Re: Casio G-Shock time sync radio

#123

Post by dingaling »

nabla9 wrote: post #77

I have Casio GW-M5600. It's a perfect watch. - Looks like classic G-Shock. - shows correct time always (time sync) - never runs out of battery (solar charging).

> I have Casio GW-M5600. It's a perfect watch.

It's very large, though. I haven't found a radio-set 'square' Casio in the Baby G-Shock range which would be a better size.

Re: Casio G-Shock time sync radio

#124

Post by markdoubleyou »

2-718-281-828 wrote: post #61

not working in SEA, though :/ there are some tricks with apps synthesizing a electromagnetic radio signal via speaker activity but i never got this to work.

My Pro-Trek syncs most nights in Seattle, but only if I leave it on a window sill with 12 o'clock facing southeast.

Re: Casio G-Shock time sync radio

#125

Post by jansan »

strangattractor wrote: post #74
vlachen wrote: post #51

I wore a G-Shock Wavecepter while serving in the U.S. Marine Corps. I recall that on both of my shipboard deployments (2004 and 2006) I was very excited to have my watch set time automatically. It indicated that I was finally nearing the U.S. East Coast. It helped to be an aircraft mechanic on night crew, as I was usually on the flight deck when it tried to set time.

Have solar atomic version. Don't wear it much these days. Mostly when I travel. Been on my dresser 2 years collecting dust but gets some sun. Picked it up the other day for a camping trip. It was both charged and had the correct date and time.

The newer ones go into sleep mode until they sense some movement. Each morning when I pick up my GW-M5610U-1 (of course with the titanium mod), the display is blank and then fills with data within a second or so. I really like the feeling that although I hopefully have a few more decades to live, this watch may be my trusted companion for the rest of my life.

Re: Casio G-Shock time sync radio

#126

Post by pkulak »

clusmore wrote: post #83
firewolf34 wrote: post #9

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.

That’s not even enough because different zones observe DST at different times, or not at all. You would have to enter your actual time zone, not an offset, like when you install an OS or something. And then if that zone ever changes, which happens a lot, the clock in your microwave will often, or always, be wrong. So now your microwave needs to be internet connected to download tz databases, and what are we even doing here.

Re: Casio G-Shock time sync radio

#127

Post by layer8 »

ilyt wrote: post #88
firewolf34 wrote: post #9

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…

Have you...used them ? 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 h…

I have a number of DCF77 clocks in my home, including small alarm clocks. No external antennas. No issues whatsoever.

Re: Casio G-Shock time sync radio

#128

Post by layer8 »

V__ wrote: post #13
firewolf34 wrote: post #9

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…

Is it really not common? I don't thing I have seen a digital clock or modern wall clock which doesn't have it. I think my Microwave has it too. Onky my oven doesn't. Is it maybe more common in Europe?

It’s common in clocks, but not in other appliances (nor in cars).

Re: Casio G-Shock time sync radio

#129

Post by bayindirh »

somat wrote: post #107
ilyt wrote: post #91

Earlier quoted context omitted.

Why you think manufacturers went into touch surfaces in cars much to dissatisfaction (that eventually caused some to back up) of customers? Every button needs a bit of plastic moulded, a (good quality) button, backlight, often LED to signal whether it is on or off, and whole control block needs microcontroller to pack it into CAN bus and CAN bus connector to send. Make whole thing a touch surface and you're saving bu…

Strictly speaking a touch screen is massively more complicated than a set of buttons. you now have billions of gates that have to be produced at nanometer scales in some of the most expensive factories on earth. The price to develop and manufacture a touch screen is many times that of a set of buttons. The fact that it is a generic interface drives the cost per unit down quite a bit. it does not hurt that the incredi…

> Strictly speaking a touch screen is massively more complicated than a set of buttons.

But, it's a commodity item, produced in many more numbers w.r.t. a A/C temperature/fan encoder w/custom shape. A bog standard Renault Clio touchscreen is comparable to a good (not high, not top) quality Raspberry Pi screen you can get from RS or AdaFruit.

The screens on Opel Mokka I drove (it has two, one for dash, one for infotainment) were extremely good at sunlight, but the dash one was so small, around 7" IIRC, to control costs. So, even if they don't pay for R&D of the screen itself, the industry is so cost sensitive, that they will cut costs relentlessly to be able to sell more of these things at a lower cost and with higher profit margins.

Also, these LCD dashes has a couple of hidden LED indicator lights around to communicate fatal things in a failsafe manner.

Car manufacturers do not bear the CapEx required to develop these screens, but bear the CapEx required for developing and prototyping physical buttons.

> I just wish we ended up with aircraft style MFD's instead of touch screens. You know those things with a screen and a row of buttons along each side.

Industry is evolving on that direction now.

Re: Casio G-Shock time sync radio

#130

Post by Ekaros »

firewolf34 wrote: post #9

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…

Just looking at those maps should explain part of it. There isn't enough coverage. So you end up with poor experience with substantial amount of people who do not get good signal.

This would likely result in lot of returns, warranty claims and so on. Just not worth it in general.

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