Monday, June 10, 2013

Stratum 1 NTP server with Raspberry Pi

Using the GPS board I recently mentioned, and a Raspberry Pi, I built a stratum 1 NTP server. I'm working on a writeup of the process, in the meantime, here's a photo of the setup.

The red wire is used to bring the pulse-per-second signal to the Raspberry Pi GPIO connector (in this case, GPIO 18, but you can use a different line if that is already in use). The GPS is powered by the Raspberry Pi via USB, this also provides a ground return path for the PPS signal. At the same time, the GPS boards appears as /dev/ttyUSB0 to the operating system on the Pi.

Thursday, June 6, 2013

GPS board

I got a GPS board in the mail, with PPS output, as well as NMEA output over USB, RS232 and Bluetooth. The plan is to build a basic NTP stratum 1 server to use at home.

Someone wrote a detailed review of this board.

A couple of photos of it on my workbench:

You can view the NMEA data on the terminal window, in this case it was being read over Bluetooth, the USB cable was just providing power.