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.

Friday, March 22, 2013

Wednesday, March 20, 2013

SDR kit inventory

Inventory complete... looks like everything is here, I can't put this project off any longer...