During these days i was searching for something modular and scalable that can gives me a clear PPS ( http://en.wikipedia.org/wiki/Pulse_per_second ) from a GPS satellite with some datas like UTC times.I’ve tested the Arduino UNO board with the Adafruit GPS module.
It’s very easy to use them on a little breadboard. The Adafruit GPS is a little receiver with many useful characteristics:
- -165 dBm sensitivity, 10 Hz updates, 66 channels
- 5V friendly design and only 20mA current draw
- Breadboard friendly + two mounting holes
- RTC battery-compatible
- Built-in datalogging
- PPS output on fix
- We have received reports that it works up to ~32Km altitude (the GPS theoretically does not have a limit until 40Km)
- Internal patch antenna + u.FL connector for external active antenna
- Fix status LED
All for 39$. You can take into your hand or create a little circuit , you neither have to configure the UNO to start collect some datas. Just connect wires in the right locations and let the receiver connect to a GPS satellite.
Using Arduino software is very easy to connect to the board’s UART (serial) and see directly satellite data with position and precise time from Cesius/Rubidium clocks inside the GPS satellites.This is a first output without putting an “echo” code inside the board (no code is required, just connect and wacth for serial output) :
But, if you want to read data in a more human format ,you can use a code and upload into the board, remember before to intall the GPS library ( you can dowload them as zip file from github https://github.com/adafruit/Adafruit-GPS-Library ) and put this code (you can also find it into examples) http://www.sidmonitor.net/gallery/pasedcode.txt you will have this output instead:
We have here a clear PPS with a freq of 1.00 Hz and a period of 1 s, anyway it’s a good result for a little gps not bigger than a coin and 40 dollars. Next step we’ll see how can build a Stratum 1 NTP server using a board (Radxa/Wandboard or Raspberry) and see the performances on a DSL link! Stay cool!