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

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 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

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

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