Saturday 27 September 2014

Weather satellite pictures update

It was a very fine autumn day today. I spent most of the morning up on the roof messing about with my antennas. One of these said antennas was for my newly built weather satellite receiver chronicled here http://g7ltt.blogspot.com/2014/07/apt-weather-satellite-pictures.html

There are still a few kinks to iron out of the system and computer control needs to be added but you get the idea ...


It seems the clock on my PC is a little off too. I guess I'll be digging into the bowels of RegEdit to force the NTP update to happen sooner.

Take a look at http://www.g7ltt.com/wxsat/ for more pictures and a timetable.

Wednesday 10 September 2014

GPS mini cape for Beaglebone Black

On a whim I bought a Beaglebone Black. Now what? I need more PC's like a hole in the head. So what to do with it? Nothing came to mind until I discovered one day that my home brewed NTP server had failed. Aha! A quick poke around the net revealed this howto. Stand well back folks.

I've been playing with the Ublox NEO-6x series of GPS receiver modules recently. They are super-simple to use and add to any project. They need only power, antenna and a serial port. So with the GPSRX being so small and simple to use a daughterboard or "cape" (why cape? UnderDog is a Beagle and he wears a cape) for the Beaglebone was a natural fit. (

The board consumes only one of the headers
The board sits on top of the BBB drawing power from it via the raw 5V line. I found that I had to increase the current on the 5V PSU that supplied the board so that I could get a reliable GPS lock but otherwise it worked first time. And as you can see below, my Linux terminal prefers it to the other available servers from us.pool.ntp.org

g7ltt@earth:~/Downloads$ ntpq -p
     remote                       refid            st t when poll reach   delay   offset  jitter
=====================================================================
*time.g7ltt.com             .GPS.            1 u    5   16  377    0.284    0.880   1.543
-tdp-ism01.exped    206.183.22.197   3 u    4   16  377   55.487  -61.764   1.003
+152-ism01.exped   129.6.15.28        2 u    9   64  377   31.547  -69.109   1.229
-upa-ism01.exped   206.183.22.197   3 u   15   64  377   43.276  -68.318   1.557
+810-ism01.exped   128.118.25.12    2 u    6   64  377   38.032  -67.287   1.023

The prototype board in service
The files in Eagle format ...