[time-nuts] 1PPS to 32.768 khz

I have this (very smart) semi-retired design engineer friend named Craig who I first queried about this clock issue. We always enjoy getting together in his lab or sitting outside enjoying the weather and good cigars. As usual I bug him with my crazy ideas as a way to educate myself or

Re: [time-nuts] 1PPS to 32.768 khz

If the heart of your clock is a micro, you may be able to reset the processor and set the time once a second fastest enough not to have any visual artifacts. Even if you have a perfect 32.768 kHz clock you still have to set the phase (time) manually and deal with DST, leap seconds, and power

Re: [time-nuts] 1PPS to 32.768 khz

e the goal is 32 kHz output. /tvb - Original Message - From: "Jim Harman" <j99har...@gmail.com> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Friday, October 21, 2016 10:42 AM Subject: Re: [time-nuts] 1PPS to 32.768 kh

Re: [time-nuts] 1PPS to 32.768 khz

I'm kind of late to the party on this one, but I think the simplest approach with the least disturbance to the operation of the original system would be to form a VCXO and PLL. Good old 4000 series CMOS stuff should be plenty fast enough. Two pieces should be sufficient. For example, a CMOS

Re: [time-nuts] 1PPS to 32.768 khz

On Thu, Oct 20, 2016 at 7:08 AM, Bob Camp wrote: > One problem with a PLL and a 1 Hz input are the values of components > you get in the loop. > The other issue is the cost of the VCXO that will get > you to 32,768 KHz. > As I mentioned earlier, the DS3231 chip (about $6.50 qty 1

Re: [time-nuts] 1PPS to 32.768 khz

On Wed, Oct 19, 2016 at 8:32 PM, Lee - N2LEE via time-nuts < time-nuts@febo.com> wrote: > > A lot of my other clocks are 6 digit NTP POE clocks so they are not GPS > accurate but I would at like them to all agree. > Can you point all of those POE NTP clocks to a common LOCAL NTP server? Time

Re: [time-nuts] 1PPS to 32.768 khz

Hi One problem with a PLL and a 1 Hz input are the values of components you get in the loop. The other issue is the cost of the VCXO that will get you to 32,768 KHz. The PLL as described by the OP would need the 1 pps divided by 2 with a lot of PLL chips. You now are locking 32768 to 0.5 Hz.

Re: [time-nuts] 1PPS to 32.768 khz

I think the suggestion to simply blast out 32768 pulses once per second at a fast rate of (say) 40kHz is the simplest yet and VERY close to what the OP asked for. This makes the average frequency near perfect but of cours with HORRIBLE phase noise but the OPonly cares about average frequency.

Re: [time-nuts] 1PPS to 32.768 khz

To: "time-nuts@febo.com" <time-nuts@febo.com> > Subject: [time-nuts] 1PPS to 32.768 khz > > Here's another way to do it for a wall clock display... set up an > oscillator/divider (or even a 555 timer) to generate a frequency close to, > but faster than 65536 Hz.Setu

[time-nuts] 1PPS to 32.768 khz

Tom nailed the issue. First problem is I was native in thinking “Oh this will be easy to interface to the NTP or GPS”. WRONG :) But the good news I am learning a lot about accurate time from you guys. The second issue is Tom is right. This is a cheap jumbo clock that at the heart uses a

Re: [time-nuts] 1PPS to 32.768 khz

I was thinking 32.768kHz VCXO and phase detector to make a simple analog PLL. I found a datasheet for a suitable VCXO and assuming a total error of 20ppm, it would only need to be divided by 2 to prevent locking to the wrong frequency making an analog PLL pretty simple. Safer to divide by 4 or 16

Re: [time-nuts] 1PPS to 32.768 khz

iginal Message - > From: "Brooke Clarke" <bro...@pacific.net> > To: "Lee - N2LEE" <l...@n2lee.com>; "Discussion of precise time and > frequency measurement" <time-nuts@febo.com> > Sent: Wednesday, October 19, 2016 12:18 PM > Subject: Re:

Re: [time-nuts] 1PPS to 32.768 khz

> Here's another way to do it for a wall clock display... set up an > oscillator/divider (or even a 555 timer) to generate a frequency close to, > but faster than 65536 Hz.Setup a 16 bit counter clocked by that signal. > When the 1PPS signal arrives, start the counter. After 65536 pulses

Re: [time-nuts] 1PPS to 32.768 khz

HI That approach would also work fine on a “internal clock” MCU. Scratch the need for a fancy timer. You may be down under 50 cents …. Bob > On Oct 19, 2016, at 7:15 PM, Mark Sims wrote: > > Here's another way to do it for a wall clock display... set up an >

[time-nuts] 1PPS to 32.768 khz

Here's another way to do it for a wall clock display... set up an oscillator/divider (or even a 555 timer) to generate a frequency close to, but faster than 65536 Hz.Setup a 16 bit counter clocked by that signal. When the 1PPS signal arrives, start the counter. After 65536 pulses the

Re: [time-nuts] 1PPS to 32.768 khz

Hi As has been already mentioned, a lot depends on what you have. The drop dead cheapest way to do it: Start with an MCU with an internal oscillator. There are *lots* to pick between. Which sort really does not matter. For example, I’ll use one that starts at 4 MHz. Divide the 4 MHz down to

Re: [time-nuts] 1PPS to 32.768 khz

/tvb - Original Message - From: "Brooke Clarke" <bro...@pacific.net> To: "Lee - N2LEE" <l...@n2lee.com>; "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Wednesday, October 19, 2016 12:18 PM Subject: Re

Re: [time-nuts] 1PPS to 32.768 khz

Hi Lee: 32768 can easily be divided down to drive the clock. So why not bypass the 32768 and drive the clock directly from the 1 PPS you now have. http://www.prc68.com/I/QuartzClk.shtml -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html The

Re: [time-nuts] 1PPS to 32.768 khz

Even if the micro controller had to directly control the LEDs on the clock your suggestion would be not only simpler bot several orders of magnitude more accurate.I'd guess that a first attempt to build a 32KHz GPSDO would not be perfect but the PPS signal is effectively dead-in perfect in

Re: [time-nuts] 1PPS to 32.768 khz

On Wed, Oct 19, 2016 at 6:15 AM, Dave Martindale wrote: > If the "big digital clock" doesn't display the time with fractional-second > precision, then it only needs to be updated at 1 Hz, which can be done with > the 1 PPS directly. Consider replacing the 32 kHz

Re: [time-nuts] 1PPS to 32.768 khz

asurement" <time-nuts@febo.com> Cc: <hmur...@megapathdsl.net> Sent: Wednesday, October 19, 2016 3:29 AM Subject: Re: [time-nuts] 1PPS to 32.768 khz > > davidwh...@gmail.com said: >> I think a PIC might be fast enough to DDS it. The output bandpass filter >> will

Re: [time-nuts] 1PPS to 32.768 khz

You guys are great. I especially like the more creative solutions that could take this project to a different level. I should have known that my request was not a simple one. :) While going from 1 PPS to 32.786 is not as easy as I had hoped what I find odd is that others must have been looking

Re: [time-nuts] 1PPS to 32.768 khz

Hi, = If you want to go Tom's picDIV route, and are lazy like me, this is one of several boards available. https://oshpark.com/shared_projects/kXG6K5Xu You'll get several copies of the bard board for under $10. Few minutes stuffing it, and you'll have a working device... Dan Hi Lee,

Re: [time-nuts] 1PPS to 32.768 khz

@febo.com Subject: [time-nuts] 1PPS to 32.768 khz First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously

Re: [time-nuts] 1PPS to 32.768 khz

If the "big digital clock" doesn't display the time with fractional-second precision, then it only needs to be updated at 1 Hz, which can be done with the 1 PPS directly. Consider replacing the 32 kHz crystal, divider chain, and microprocessor with a new microcontroller that takes 1 Hz input and

Re: [time-nuts] 1PPS to 32.768 khz

Lee, Another option might be something like this: http://qrp-labs.com/progrock.html it is a standalone ATTiny based device which uses a plug in Si5351a synthesizer. Output frequencies from as low as 3.515 khz to a 100+ MHz can programmed and can be GPS disciplined suing a GPS' PPS. There are

Re: [time-nuts] 1PPS to 32.768 khz

davidwh...@gmail.com said: > I think a PIC might be fast enough to DDS it. The output bandpass filter > will cure a lot of sin. Using a dedicated switched capacitor filter would > be fun but more expensive. There are two parts to a DDS like setup. One is the math for the DDS and then

Re: [time-nuts] 1PPS to 32.768 khz

First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously wrong with me now I know there are others

Re: [time-nuts] 1PPS to 32.768 khz

2LEE" <l...@n2lee.com>; "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Wednesday, October 19, 2016 7:26 PM Subject: Re: [time-nuts] 1PPS to 32.768 khz What you want is a GPSDO. Most people here build these to run at 10MHz. But you nee

Re: [time-nuts] 1PPS to 32.768 khz

On Tue, 18 Oct 2016 22:59:42 -0700, you wrote: >> 1. Does anyone know of a device that will take a 1PPS GPS timing signal and >> generate a 32.768 kHz sine wave output ? I have big digital clock that uses >> an 8 bit micro processor and an external 32.768 crystal. Obviously the >> external

Re: [time-nuts] 1PPS to 32.768 khz

What you want is a GPSDO. Most people here build these to run at 10MHz. But you need one that runs at 32768 kHz. Try this: Divide the crystal oscillator's output by 32768. This will give you one Hz. Compare the phase of this with the phase of your PPS from the GPS. Push and pull the crystal

Re: [time-nuts] 1PPS to 32.768 khz

> 1. Does anyone know of a device that will take a 1PPS GPS timing signal and > generate a 32.768 kHz sine wave output ? I have big digital clock that uses > an 8 bit micro processor and an external 32.768 crystal. Obviously the > external crystal is awful for accuracy. I don't know of any

Re: [time-nuts] 1PPS to 32.768 khz

. The older I get, the less I require precision time. YMMV. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Lee - N2LEE via time-nuts Sent: Tuesday, October 18, 2016 9:03 PM To: time-nuts@febo.com Subject: [time-nuts] 1PPS to 32.768 khz First let me say

Re: [time-nuts] 1PPS to 32.768 khz

- From: "Lee - N2LEE via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Tuesday, October 18, 2016 7:03 PM Subject: [time-nuts] 1PPS to 32.768 khz First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know

[time-nuts] 1PPS to 32.768 khz

It might be easier to go the other away around... take a GPS receiver with a programmable output frequency and set it to produce 32768 KHz. The Venus timing receivers can produce accurate output frequencies (but with a fair amount of jitter, which would be irrelevant to a clock display).

Re: [time-nuts] 1PPS to 32.768 khz

Hi Lee, It's not exactly what you asked for, but for your clock you might give this a try, or consider using the underlying DS3231 chip directly. https://www.adafruit.com/product/255 It is basically a much more accurate and stable than usual 32KHz oscillator, with a TCXO that you can actually

[time-nuts] 1PPS to 32.768 khz

First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously wrong with me now I know there are others