What have I done with the Raspberry Pi?
- Built a stratum-1 NTP server with
microsecond-level offsets and a power consumption of less than 4 watts.
The Web page has information about interfacing a GPS receiver to the Raspberry
Pi, choosing between various receiver options, and how to compile NTP from
the source for added options.
I hope you will find the page interesting, and perhaps
build a GPS-locked stratum-1 NTP server yourself for your own network or
perhaps for portable operation. GPS receivers similar to this have been used
in the recent Babbage adventure - the
Teddy who jumped from Space - about which you may have read in the Telegraph,
or seen on the BBC.
RasPi-4 - timekeeping
- Built a Digital Wall clock using the
Raspberry Pi - synchronised with NTP, of course! The Web page
discusses setting up the Pi to just fill the analogue TV screen, and uses a
high-performance programming language (Free
Pascal with Lazarus) which can work on Windows, the Mac, or
- dump1090 - receiving aircraft location signals on 1.09 GHz with a cheap TV dongle and feeding the
results to Plane
Plotter over a Wi-Fi link, in a server-client configuration. This allows you to put the receiver
right up close to the antenna, avoiding an expensive (or lossy) piece of
cable, and avoiding the need for a cable run at all. It's not much more than following someone else's instructions, but at least
I can vouch for every command on that page, and perhaps you will find
something useful there.
- Using an Airspy - A
development of the software above, airspy_adsb is advanced version of ADS-B
software, designed to work with the Airspy hardware. This combination
provides noticeably better performance than the usual RTL dongle, but
requires a model 2B Raspberry Pi so that it can run several threads
Sample results: http://airspy.com/adsb/
Download location: http://airspy.com/download/
- Monitoring the Raspberry Pi - as most of my
Raspberry Pi cards are used headless - i.e. without a keyboard or monitor -
I wanted to monitor what was happening remotely to keep an eye on resource
usage. In addition to monitoring the NTP Server operation with standard
NTP commands and Perl scripts, I've added general SNMP
support (Simple Network Management Protocol) which allows monitoring of
the network I/O, disk space, CPU
temperature and, with a little additional hardware, ambient
temperature monitoring as well.
RasPi-4 - outside temperature monitoring
RasPi-4 - radiator temperature monitoring
RasPi-4 - air pressure monitoring
A Raspberry Pi illuminating one of Babbage
Babbage is the bear who jumped
from 39 km to set a world record!