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SimbaTLK1
Rawrrr
join:2001-09-07
Pittsburgh, PA

SimbaTLK1

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Looking for an NTP clock

Does anyone know if anyone sells either complete or in a kit some kind of hardware (not software on a computer) clock that can sync with NTP over a lan or WLAN?

I've seen a few examples of people making them out of Arduinos. I don't have any experience with them, but it looks like to get that working you'd need at minimum of an arduino, a network shield (either wired or wireless) and then whatever other hardware I'd need to make a bank of 7 segment LEDs work. (something like this but with network hardware instead of a RTC: »arduino-for-beginners.bl ··· and.html

Then I'd have to write the code to tie all that together.

That sounds like more than I want to get into. Other options include GPS clocks (and maybe RF clocks, do they still make those?) but I wouldn't be able to get a very good signal indoors.

Anyone know of any NTP clocks?

alphapointe
Don't Touch Me
MVM
join:2002-02-10
Columbia, MO

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alphapointe

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They're available ready-built, but they ain't cheap...

»www.ebay.com/itm/MasterC ··· -content

I've thought about doing that myself with an arduino or a raspberry pi, but it's not high on the priority list...

tschmidt
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Milford, NH
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said by alphapointe:

but they ain't cheap.

Boy you can say that again.

Be better to use an old laptop/tablet than pay that much for a 7-segment clock.

Well at least it supports DST but it does not have a web interface it needs to use special software to configure it.

I've run into this limitation on some networking gear. It requires the NTP server IP address. Fine of you are running your own local server but does not appear any way to use a URL like: us.pool.ntp.org

alphapointe
Don't Touch Me
MVM
join:2002-02-10
Columbia, MO

alphapointe

MVM

Yeah, I'd be more likely to buy another Sony Dash for ~$50 than to pay that much for a clock...

I had to set up an NTPd server myself because of the IP-only limitation in a lot of my older gear... I guess back then, pool.ntp.org was unheard of...
lutful
... of ideas
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join:2005-06-16
Ottawa, ON

lutful to SimbaTLK1

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You could sync the system clock on an old PC and drive an external serial display. VB (or C#) source code for both purposes are available online.
said by SimbaTLK1:

... maybe RF clocks, do they still make those? ... but I wouldn't be able to get a very good signal indoors.

Billions of indoor clocks stay reasonably accurate using atomic clock broadcast stations like WWVB. They even work in tunnels and underground parking lots because of the low 60Khz RF frequency.

You can buy wall and desktop clocks from $10 or get a cheap WWVB kit to drive your own serial display.

SimbaTLK1
Rawrrr
join:2001-09-07
Pittsburgh, PA

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SimbaTLK1

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»www.joejaworski.com/wwvb

There is an interesting project someone built to use with WWVB although it requires making a PCB and where i live (PA) the signal would only be come through at night. NTP would be a source it could sync with every hour.

Too bad those clocks are so expensive

I had another idea though. I wonder if something like raspberry pi could be used for this purpose? It runs linux, would be able to run ntpd, and even has a serial port. If some sort of RS232 to segmented LED display could be built that might work. (Perhaps something like this: »www.sparkfun.com/products/11443)

Or even better: »mjo.tc/atelier/2012/08/p ··· 638.html

What do you guys think of that idea?

leibold
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I have attached to the very same desktop on which I'm typing this message a Parallax GPS Module (PMB-648 SiRF) and use it as a reference clock for NTP (xntpd on OpenSuSE).

The module works fine with 3.3V or 5V supply voltage and outputs a serial signal in TTL and RS-232 voltage levels. I have attached it to a USB to Serial adapter (osepp FTDI breakout board) and I'm getting the voltage for the GPS module from the USB bus.

I bought the GPS module because it was inexpensive and I wanted to experiment with it. Timekeeping was an afterthought and as it turns out this module isn't a good choice for that purpose: it doesn't have a dedicated PPS (pulse per second) output which is really needed for stable sub-second precision. The most frustrating part is that the chip used inside the module actually has such an output (TM = timemark) but the pcb doesn't make it accessible
While it isn't a good reference clock (high jitter) it does work and it was surprisingly little effort to setup.

For better results:
- use a real serial port instead of a USB to serial converter because USB will introduce variable latency especially if the same bus has other devices attached to it (note that this means you will need to find a power source for the GPS module).
- use a GPS module that has a PPS output for precise triggering of the start of each new second (the NMEA string on the serial line may be delayed by internal processing overhead inside the GPS module).

SparkChaser
Premium Member
join:2000-06-06
Downingtown, PA

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Now this is a clock



Bruschi
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join:2001-04-16
Cape Cod

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nvm
public
join:2002-01-19
Santa Clara, CA

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said by SimbaTLK1:

Does anyone know if anyone sells either complete or in a kit some kind of hardware (not software on a computer) clock that can sync with NTP over a lan or WLAN?

The mbed kit can do this for $50.
»mbed.org/cookbook/NTP-Client
»mbed.org/users/4180_1/no ··· d-clock/
code to drive variety of displays is also available.

GPS usually needs an outdoor antenna.

leibold
MVM
join:2002-07-09
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ZyXEL P-663HN-51

leibold

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said by public:

GPS usually needs an outdoor antenna.

That is generally correct, but there are now some GPS receivers that are sensitive enough to provide reliable timing and position data even indoors (depending on construction type). This was in fact part of my original experiments and I'm happy to report that in a typical single family home with wood frame construction my GPS receiver "sees" 4 to 8 GPS satellites (away from windows, in the middle of the house).

The GPS module I'm using is based on the SiRFstarIII GPS microcontroller chip which has a reputation for high sensitivity. There are now newer (possibly even better) products from SiRF as well as similar chips from other companies which have allowed the price for older (but still excellent) GPS modules to drop significantly.
dmoisan
join:2003-03-25
Salem, MA

dmoisan

Member

said by leibold:

said by public:

GPS usually needs an outdoor antenna.

That is generally correct, but there are now some GPS receivers

I found it more useful to use the GPS on the server side and have a separate display.

At our TV station, we've been trying to find a solution too.

It was easier to get the server side serving time--we used a Garmin GPS-18LVC on a serial port with Meinberg's Windows NTP port. I strongly recommend getting a GPS with working PPS. It's that important. My first GPS that was also a SirfIII module did not have good PPS.

At home I also have the Garmin and I got a Beaglebone running ARM Linux that will run ntpd. Total overkill for a display.

A good platform for an NTP clock would be the Netduino Plus or the Netduino Go. I have the Plus and will make mine into a display.

I can't remember my own blog URL and I'm typing from Android, but look for #twatch NTP: I repurposed a Twitter appliance into my first NTP display. It bugs the hell out of me that we can't have one premade that's not made of expensivum.
lutful
... of ideas
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join:2005-06-16
Ottawa, ON

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said by SimbaTLK1:

I wonder if something like raspberry pi could be used for this purpose? It runs linux ...

BTW you can also run android on those cheap ARM/USB dongle computers. Google's java ntp-sync project: »code.google.com/p/ntp-sync/

*** However, your total system cost with the display will be higher than commercial WWVB clocks.

The RF front-end and baseband design is not that complex if you dabble more with electronics than software. Have a look at the 60Khz signal description and schematic for a Nixie tube clock design by Jeff Thomas: »www.amug.org/~jthomas/wwvb.html
lutful

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said by public:

said by SimbaTLK1:

... some kind of hardware (not software on a computer) clock that can sync with NTP ...

»mbed.org/cookbook/NTP-Client

Your mbed link reminded me of the tiny uIP stack which includes the leanest possible NTP client and uIP can be ported to almost any microcontroller (or embedded computer) platform with LAN port. We did it for Ubicom IP2K back in 2004 and I notice there are ports for PIC, AVR, MSP430 etc.

*** SimbaTLK1 ... NTP message decoding, clock date/time formatting, driving the serial display ... are really software tasks. The hardware can be almost any embedded system.
Tig
join:2006-06-29
Carrying Place, ON

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I'm not sure if this suits your purpose, but If all you want is time display rather than a project, cell phones get an accurate time signal and smart phones have NTP apps.
I put the battery back in an android phone that I discontinued a couple months ago. It gave me the no service message since it has no provider contract, but it still had the correct time.
Wifi of course still works and if you want NTP time rather than the unknown stratum provider time, you can add an app.

SimbaTLK1
Rawrrr
join:2001-09-07
Pittsburgh, PA

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said by lutful:

*** SimbaTLK1 ... NTP message decoding, clock date/time formatting, driving the serial display ... are really software tasks. The hardware can be almost any embedded system.

I meant not software as in I don't need a program on my computer to display/sync time, but a little box I can put in my living room.

There some good information here from everyone. Thanks for the input

cowboyro
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join:2000-10-11
CT

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I have a self-made clock based on the ATMEGA microcontrollers with uIP for TCP layer. If you're interested I'll give you the source code. I also have a library for timezone offsetting with DST.
Uses a Seiko S35390A for RTC, which has programmable drift, so it should stay very well in sync even without internet connection for a day or two...
dmoisan
join:2003-03-25
Salem, MA

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I found my NTP clock blog post: »davidcmoisan.wordpress.c ··· display/
There's a link to my source code; my clock used the Microchip TCP stack but I believe it could work with uIP as well.