5 ms·

Interesting. I do like that it's open-source hardware. Note that you can build your own, with a raspberry pi and a GPS add-on board that sends a 1 pulse-per-se

by privong 10y ago

Interesting. I do like that it's open-source hardware. Note that you can build your own, with a raspberry pi and a GPS add-on board that sends a 1 pulse-per-second signal through the GPIO pins. Sample instructions here: http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html And the GPS board can be purchased here: https://store.uputronics.com/index.php?route=product/product&path=60_64&product_id=81 https://store.uputronics.com/index.php?route=product/product...

ryan-c 10y ago
I built one of these a while back, works very well. Current status: associd=0 status=011b leap_none, sync_pps, 1 event, leap_event, version="ntpd 4.2.7p481@1.2483 Tue Nov 25 05:07:16 UTC 2014 (2)", processor="armv6l", system="Linux/4.1.13+", leap=00, stratum=1, precision=-18, rootdelay=0.000, rootdisp=1.180, refid=kPPS, reftime=db8dafdb.d2b0f5b9 Thu, Sep 22 2016 1:18:19.823, clock=db8dafe8.c014ef24 Thu, Sep 22 2016 1:18:32.750, peer=42535, tc=4, mintc=3, offset=-0.000614, frequency=-44.146, sys_jitter=0.003815, clk_jitter=0.004, clk_wander=0.000 I believe that the jitter values are in milliseconds.
- voltagex_ 10y ago
  Where does the GPS antenna have to sit? My ISP provides a stratum-3 (?) timeserver, but it'd be nice to put a Pi or two to use.
  - ryan-c 10y ago
    It's just sitting on a windowsill.
DashRattlesnake 10y ago
This device has a temperature-compensated oscillator, and I'm guessing you could never match its performance with a cheapo board like a Raspberry Pi.
- privong 10y ago
  > This device has a temperature-compensated oscillator, and I'm guessing you could never match its performance with a cheapo board like a Raspberry Pi. The 1 PPS timing signal comets from the GPS shield, not the pi. I didn't see any specific info on the crystal the shield has (the website just says "RTC crystal"). So if the shield were modified with a temp-compensated crystal, it should do just as well.

by privong 10y ago

ryan-c 10y ago

I built one of these a while back, works very well. Current status: associd=0 status=011b leap_none, sync_pps, 1 event, leap_event, version="ntpd 4.2.7p481@1.2483 Tue Nov 25 05:07:16 UTC 2014 (2)", processor="armv6l", system="Linux/4.1.13+", leap=00, stratum=1, precision=-18, rootdelay=0.000, rootdisp=1.180, refid=kPPS, reftime=db8dafdb.d2b0f5b9 Thu, Sep 22 2016 1:18:19.823, clock=db8dafe8.c014ef24 Thu, Sep 22 2016 1:18:32.750, peer=42535, tc=4, mintc=3, offset=-0.000614, frequency=-44.146, sys_jitter=0.003815, clk_jitter=0.004, clk_wander=0.000 I believe that the jitter values are in milliseconds.

voltagex_ 10y ago
Where does the GPS antenna have to sit? My ISP provides a stratum-3 (?) timeserver, but it'd be nice to put a Pi or two to use.
- ryan-c 10y ago
  It's just sitting on a windowsill.

DashRattlesnake 10y ago

This device has a temperature-compensated oscillator, and I'm guessing you could never match its performance with a cheapo board like a Raspberry Pi.

privong 10y ago
> This device has a temperature-compensated oscillator, and I'm guessing you could never match its performance with a cheapo board like a Raspberry Pi. The 1 PPS timing signal comets from the GPS shield, not the pi. I didn't see any specific info on the crystal the shield has (the website just says "RTC crystal"). So if the shield were modified with a temp-compensated crystal, it should do just as well.