Clock Question

I'm sure I could write you a program to do something like that pretty quickly. The question is, what clock is going to read data from a serial port?

An even more important question is, isn't it going to drive you nuts knowing that any clock you drive from the serial port is going to be milliseconds (yes, milliseconds, and probably many of them!) off target?

Just think about it. You'll end up sitting in your rocking chair, staring at the clock, thinking, "Damn, that last tick should have happened earlier... damn, that one too... damn, that one too... damn, that one too..."

In the morning, your wife will find that you've spontaneously combusted, and all that's left is your slippers, part of your robe, and what many people will come to believe was simply an urban legend all along.

"Jim Thompson? Hell, son, he's like Bob Widlar. He never really existed, it's just a bunch of stories that got handed down through generations of engineers."

Is that what you really want, Jim? Even your kids would begin to believe the legend after a while. One day, your daughter would recount the story of how you died: "Well, dad had bought this JATO rocket at the swap meet, and he welded it to his old Impala one day... You can still see the hole in the side of South Mountain where he augered in."

Trust me. What you want is a Westclox Big Ben. They're simple. They're cheap. They're probably not made any more. But I'm sure you can find one on Ebay. They need to be reset every week. But who cares? You'll never look at one of them and say, "Damn, that last tick should have happened earlier..."

-- Mike --

If you are simply looking for accuracy, you can just build a simple receiver for 60Hz power line emissions, and use that for the timing.

I've seen schematics on the web, but I'm sure you can come up with something better with one lobe tied behind your back.

Regards, Bob Monsen

on

at

earlier..."

You should have clicked "Send" a lot earlier.

(couldn't resist)

"Off the peg" USB-powered 7-seg LED displays...

Docs & software downloadable. Routine to spit out computer clock time is relatively trivial.

"Mike" wrote ...

You can write the software to take any time delays into account. You can even compensate for the speed of light from the display to Mr. Thompson's retinas (including the delay through his optic nerves to his cereberal cortex. Of couse, it will be *slightly* off for others! :-)

Get any quartz wall clock. You know, the ones that can be anything on the outside, but all have the same square movement inside.

Now:

Choose a time in hours and minutes. The time cannot be 12:00 for reasons obvious later.

Now drill six small holes in the face of the clock, two pairs positioned where the hour and minute hands will be located at your chosen time. The third pair is positioned at the 12:00 or zero position, where the second hand will pass above it. Insert an infrared LED and a photo transistor in each pair of holes.

Next step is to glue a small pulley, rubber band, and motor to the adjusting wheel on the back of the the clock movement.

Also, remove the battery and provide a controllable 1.5V source for the clock.

Wire the motor, power leads, and phototransistors to a microcontroller and serial port.

The software: Two minutes before synchronization time, begin watching for the second hand to come around to the zero position. As soon as it does, remove power from the clock. Then engage the motor and slowly advance the clock until the hour and minute hands are reported to be in position. Wait until the very instant that the computer time reaches the synchronization time, and then re-engage the clock power.

You now have a NIST-synchronized wall clock.

Citizen watch crystals are readily available for this. You use a

16-bit PIC timer to get a 1 sec interrupt.

--
Best Regards,
Mike

I'm sure Jim can design a clock.

If you know the latency and write the program so that it changes the process priority to "real time", gets the time and sends the data, and then returns to normal prioity, the clock PIC could adjust for that. You'd also have to write the app to check the processor speed, OS and anything that might change that latency, calculate it in the app, and send that data to the PIC.

Damn. You've got him all but dribbling spit out the side of his mouth.

But that confounded alarm might be the end of him.

--
Best Regards,
Mike

Apart from those UNIX LINUX replies, it also is the DOS syntax to redirect the output, but you'd want the time command, and the device would be lpt1 for parallel port or *maybe* com1 for serial. I just tried

time > c:\o1t.txt and got

The current time is: 1:15:26.35 Enter the new time:

in a text file.

you have to either send ctrl-c or hit return to exit without entering a new time.

time > com1 gave me the blank stare also, so I hit return and got the command prompt back. I can only assume the ascii time string went to my serial port, but I have no way to check it right now.

You can use the winders api function ShellExec or whatever (i always have to look it up) to execute these command lines. A batch file would do it also. You could run the batch file from your task scheduler.

--
Best Regards,
Mike

Yeah, but it would be a VBA. VB script runs in ASP. A VBA could be run as a service under NT and later. Alternately, you could put it in the Start Up Programs "folder" or task schedule it.

MSComm is the control to use in VBA as you said.

BTW. VB sucks. C++ rules. MSComm can be accessed from a winders app in C++.

--
Best Regards,
Mike

You left out the major advantage of the Big Ben alarm clock: It will still wake you up during a power failure, without the expense of a UPS.

Wow! How do those things keep time with NO power? :-)

(OTOH, more of what we consider "electronic" devices are being run by essentially clock-spring (or manual crank) "power".

Take a look at the LCD panels that the case modders use to display things like CPU temp. Most of these connect via RS232 and I'm sure some of them must have a time display.

Right- and forget it when this guy bids against you on EBAY- he pays anything to get what he wants- must spend $40K annually just for junk instruments- and a lot of Porsche accessories IIRC.

It's for the pizzazz ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Why the quotes? Power is energy / time, whether electrical, mechanical or neutrino flux.

I found this thread because I am relying on a network of XP machines to be synchronized to the second for an application I am building. Much to my surprise, the two XP machines at my desk get out of sync very quickly. Within a couple of hours of synching to time.windows.com one machine is about 45 faster than the other.

So, even if you find out how to drive a clock from a PC, I wouldn't expect it to necessarily be particularly accurate. You could in anycase merely dedicate a computer to displaying the "correct" time anyway.

I have a CASIO Waveceptor Watch that attempts to get synched up with WWV in Fort Collins every night. That might be your cheapest solution.

I use Socketwatch, setup for synchronization once an hour (always connected cable high-speed Internet). It is rare when I am off by more than 25ms.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Download any of the free NIST utilities and set it to run every 5 minutes or so.

Cheers!

Chip Shults