Tag Archives: Raspberry Pi

Building a Raspberry Pi magnetometer network

Source: Ciarán D. Beggan and Steve R. Marple

Ciarán Beggan of the British Geological Survey describes how a network of 9 Raspberry Pi magnetometers were deployed to schools around the UK to measure geomagnetic storms

As computers such as the Raspberry Pi and geophysical sensors have become smaller and cheaper it is now possible to build a reasonably sensitive system which can detect and record the changes of the magnetic field caused by the Northern Lights (aurora).

Though not as accurate as a scientific level instrument, the Raspberry Pi magnetometer costs around 1/100th the price (about £180 at 2019 prices) for around 1/100th the accuracy (~1.5 nanoTesla). However, this is sufficient to make interesting scientific measurements.

During 2017, a network of 9 Raspberry Pi magnetometers were deployed to schools around the UK from Benbecula to Norwich. On September 8, 2017 a large geomagnetic storm was captured by the school magnetometers. Using these data and the array of other magnetometers around the North Sea, we were able to recreate the spatial and temporal changes of the magnetic field during the storm in great detail. The two phases of the storm show the westward (night time) and eastward (daytime) flow of the auroral electrojet currents in the ionosphere.

Source http://www.mist.ac.uk/nuggets

Download the paper Building a Raspberry Pi school magnetometer network in the UK
https://www.geosci-commun.net/1/25/2018/gc-1-25-2018.pdf

Click here to read at the Southgate ARC.

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Updated Raspberry Pi image for SDRplay software defined radios

Build a 433 MHz radio chat device with the Raspberry Pi

Raspberry Pi Vintage Radio

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This project was a winner in the Maker Share Mission May contest. While not strictly shortwave, of course, many of SWLing Blog readers enjoy, as I do, all things radio, and especially creative and new expressions of radio. Here is a brief excerpt from the MakerShare posting:

Vintage radios are fascinating. At one point the radio was the main method for mass communication of news and entertainment and was manufactured in a variety of styles to be prominently displayed in a home. Unfortunately, many vintage radios that have been physically preserved no longer function and it is impractical for them to be repaired. Described is the design and implementation of the Raspberry Pi Radio (RPiRadio), a device that bypasses the analog electronics of a vintage radio and digitally recreates the behavior of a vintage radio that is able to be tuned to vintage radio programming.

The whole posting may be found here, with extensive details on the building of the radio and how it was programmed for sound replicating the vintage radio era.

While I love tinkering with old radios and trying to bring them back to life, some radios are just beyond reasonable repair. This can bring old radios back to life in a way which seeks to honor their past – a very cool idea indeed!

Robert Gulley, AK3Q, is the author of this post and a regular contributor to the SWLing Post. Robert also blogs at All Things Radio.

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Turning the Raspberry Pi 3 B+ into a stand-alone SDR

The new Raspberry Pi 3 B+ and a number of RPi projects

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Last month, on “Pi Day” (March 14, 2018) an upgraded Raspberry Pi 3 B was announced on the Raspberry Pi website. The new $35 B+ sports a few performance enhancements over the original–most notably:

A 1.4GHz 64-bit quad-core ARM Cortex-A53 CPU
Dual-band 802.11ac wireless LAN and Bluetooth 4.2
Faster Ethernet (Gigabit Ethernet over USB 2.0)
Power-over-Ethernet support (with separate PoE HAT)
Improved PXE network and USB mass-storage booting
Improved thermal management

Here’s a short promo video posted with the announcement:

Click here view on YouTube.

I immediately navigated to my favorite Raspberry Pi source–AdaFruit–and requested a notification when the new units were available to purchase. A few weeks later, I got the notification and placed an order within minutes (you see, when the Pi 3 B was first released, I hesitated a day and had to wait a few weeks for the second shipment!).

I received my RPi 3 B+ a few days ago:

I immediately attempted to put this unit into service but learned that it requires the latest firmware which was only released a week or so ago. If you have have an RPi 3 B+, here’s where to fetch the latest firmware:

NOOBS:
https://www.raspberrypi.org/downloads/noobs/
or if you want Raspbian:
https://www.raspberrypi.org/downloads/raspbian/
and install on SD per instructions here:
https://www.raspberrypi.org/documentati … /README.md

After receiving this latest Pi, I quickly realized I’ve bought a number of Raspberry Pi models over the years and currently have them in service for a variety ofc projects. Here’s a list of all of my current Pi-powered applications:

A FlightAware ADS-B feed
A LiveATC feed of airport KHKY
A desktop computer for my kids to learn Python and do homework
A headless remote unit for transferring large files and archiving the full Shortwave Radio Audio Archive
A Raspberry Pirate FM transmitter
Two RACHEL-PI systems (English and French) I’m evaluating for use with ETOW (Thanks for the tip, Mark Phillips!)
And, inspired by Tudor, I plan to build a portable SDR station around my AirSpy HF+ and SDRplay RSP1A

That’s a total of seven RPi projects that are in service at time of posting!

As I mentioned earlier, I try to buy most of my Pi equipment from the amazing AdaFruit retailer–I like supporting what they do even if I pay a small premium.

But AdaFruit seems to rarely have stock in some of my favorite Pi bundle packages. If I’m buying a Raspberry Pi for a new application, I look for a package with at least a case, a 2.5 amp power supply, a 32 or 64GB MicroSD card, and two heat sinks (though I’m not certain the B+ needs a heatsink). I tend to grab this one or this one from Amazon (affiliate links).

Post readers: Have you ever used a Raspberry Pi? If so, in what sort of applications? How many do you own? Please comment!

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Tudor demos his portable Raspberry Pi-powered AirSpy HF+

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Many thanks to SWLing Post contributor, Tudor Vedeanu, who has kindly shared details about his portable Raspberry Pi system which now can run the AirSpy HF+ SDR.

Tudor writes:

I bought the RPi to use it as a Spyserver for my Airspy HF+ SDR.

My main radio listening location is a small house located on a hill outside the city and there is no power grid there (it’s a radio heaven!), so everything has to run on batteries and consume as little power as possible.

My first tests showed that the Raspberry Pi works very well as a Spyserver: the CPU usage stays below 40% and the power consumption is low enough to allow it to run for several hours on a regular USB power bank. If I add a 4G internet connection there I could leave the Spyserver running and connect to it remotely from home.

Then I wondered if the Raspberry Pi would be powerful enough to run a SDR client app. All I needed was a portable screen so I bought the official 7” touchscreen for the RPi.

I installed Gqrx, which offers support for the Airspy HF+. I’m happy to say it works better than I expected, even though Gqrx wasn’t designed to work on such a small screen. The CPU usage is higher than in Spyserver mode (70-80%) but the performance is good. Using a 13000 mAh power bank I get about 3.5 hours of radio listening.

I made a video showing how it works:

Click here to view on YouTube.

This is fantastic, Tudor. Thanks for taking the time to put together a video for us. I’ve just ordered the latest Raspberry Pi 3 (Model B+). It has slightly more horsepower than the previous Pi3. Tudor, you’ve inspired me to grab the 7″ touch display as well and try my hand at running the AirSpy HF+ portable.

I’m not sure if the Raspberry Pi 3 will be able to record spectrum without hiccups, but it’s certainly worth a try.

As you tweak your system, please keep us in the loop!

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