NTP - some notes from Rich Schmidt

A new GPS/PPS add-on

Rich writes: I have finally gotten my hands on the Raspberry Pi Zero and this new "RPi GPS add-on V2" (eBay $28 with mouse antenna). I'm building an NTP server for under $100. Here is the new GPS board, uBlox NEO-6M with 1 PPS header on an RPi 2. Click a picture for a full-sized image.

Here is the same board mounted below a Raspberry Pi Zero:

and some performance data:

"ntpq -c rv"
associd=0 status=0128 leap_none, sync_pps, 2 events, no_sys_peer,
version="ntpd 4.3.75@1.2483 Sun Oct 4 20:48:59 UTC 2015 (1)",
processor="armv6l", system="Linux/4.1.13+", leap=00, stratum=1,
precision=-19, rootdelay=0.000, rootdisp=1.015, refid=PPS,
reftime=da54b15d.2bfb5e3f Thu, Jan 28 2016 15:25:17.171,
clock=da54b15e.964b0d5c Thu, Jan 28 2016 15:25:18.587, peer=43636, tc=4,
mintc=3, offset=0.004, frequency=-3.422, sys_jitter=0.001907,
clk_jitter=0.002, clk_wander=0.001, tai=36, leapsec=201507010000,
expire=201512010000

A US $65 NTP server

Raspberry Pi Zero $20
uBlox NEO-6 GPS with PPS header and C&Q Microwave ceramic patch antenna,
$18 at dx.com
microUSB-Ethernet adapter $12
power supply $5
16GB microSD card $5
wood Zebra case $5
Total $65

Connection details:

Performance:

More Information....

Rich's PDF paper is here, with a local copy here.

My thanks to Rich (schmidt.rich [at] gmail {dot} com) for allowing reproduction of this information.