Radio Analyser: New Program for Plotting DSDPlus Statistics

Thank you to Matthew Cowley for submitting news about his new program called "Radio Analyser". Radio Analyser is a program that imports DSDPlus radio and group files into a postgresql database. The data can then graphed on the web interface allowing you to view talk group and radio statistics. DSDPlus is a program that can be used to listen in to digital P25, DMR and other digital voice protocols with an RTL-SDR or similar SDR.

Matthew writes the following, and some screenshots of the interface and graphs are shown in the slider and the end of the post:

I've been learning Ruby on Rails and as a first project I wrote a project that you host at home which imports the DSDPlus.radios and DSDPlus.groups files and displays their activity in graph form. It will show you total site activity, talk group activity and radio activity.

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Reprogramming a €15 USB Audio Dial to work as an SDR VFO Knob

Thank you to Tysonpower (aka Manuel DO5TY) for submitting information about how he's managed to convert a cheap €14.33 USB audio control dial into a VFO tuning knob for use in SDR programs like SDR-Console V3. He writes:

I sometimes miss a VFO Knob while using my SDRs, especially with SSB Signals or CW where you need to adjust the Frequency very fine.

Because of that I got myself an Audio Dial with USB, reverse engineered it somewhat and wrote a new Firmware for the STM32 used in the USB Dial.

It all worked out and it now simulates a mouse wheel with three different scroll speeds. There is also a Mute Function when you long press the Button.

I had a lot of fun during this project, even when it was a lot of time just for a VFO Knob :)

Manuel's blog post goes into deeper detail on how he reverse engineered the knob and how he re-programmed the STM32 microprocessor. He also includes the HEX file if you want to purchase the same unit and reflash it. His video below shows the modified knob in action.

[EN subs] VFO Knopf für SDRs aus einem Lautstärkeregler

Experimenting with an Ultrasonic Sensor Connected to an Airspy HF+

Software defined radios can have many more applications other than just radio. For example, it's possible to connect an ultrasonic sensor which outputs a waveform at some frequency above DC directly to the input of an SDR. We can then simply treat the sensor output as an RF signal, and view it in any SDR compatible software that shows us a spectrum. Normally you'd use a microcontroller with ADC to process the output of these sensors, but using an SDR makes visualizing and experimenting with these sensors much easier.

Over on YouTube W1VLF has uploaded a video showing his experiments with an ultrasonic sensor connected to his Airspy HF+. In his experiment he places the Airspy HF+ with directly connected ultrasonic sensor in one room, and sets up an ultrasonic emitter in another room. He then uses SDR# to view the 24 kHz ultrasonic sensor signal output on the computer. As he moves the sensor around it's possible to clearly see the doppler shift of the ultrasonic sound waves on the waterfall.

In the past we've also posted about Jan de Jong who experimented with using a piezo speaker connected to an SDRplay RSP1A to detect the ultrasonic navigation sounds from bats.

AirSpy Discovery Its not just for RF anymore

SignalsEverywhere: The Ethics of Decoding and Sharing Private Information with SDRs

Over on the SignalsEverywhere YouTube Corrosive has uploaded a new video that addresses the ethics about decoding private information with SDRs. The radio spectrum is full of private communications with little to no security around it. For example hospital pagers in many countries and cities are completely unencrypted and easily decoded by anyone who can run a radio and install software on Windows. These messages often contain very private patient data. Another example he gives is Inmarsat AERO Medlink voice communications, and how he's seen full phone calls being shared online.

In the video Corrosive discusses the ethics about publicly sharing these private communications, even if they may be legal to receive and share in your country. He argues that sharing someones private data and phone calls on the internet is in poor taste and is not okay, which I think is something everyone should be able to agree with.

SDR Ethics | We Need to Talk!

However, on the other side of the coin several responses to his video on Reddit share a different point of view. On that forum several expressed disagreement, noting that it's because these services are so insecure, that we should actively be sharing intercepted messages and trying to raise outrage and awareness about these privacy flaws. The argument stems from the idea that many information security researchers seem to take: if the public is not aware about their lack of privacy, only the bad guys will be taking advantage, and nothing will end up being properly secured by companies.

We've seen this approach taken by information security artists in the past like the Holy Pager art installation in New York. The temporary installation used a HackRF to continuously print out all pager messages being broadcast in an attempt to raise awareness about what private information is being sent for anyone to read. However, it may be one thing to share private data with a few art gallery patrons, versus the entire internet.

I think we should all at least agree on a middle ground. If you are listening/decoding radio services that are meant to be private but are unsecure for all to listen to, at least keep it to yourself, and don't share peoples private conversations/data on the internet. If you want to raise awareness about the lack of security to put pressure on companies, censor peoples private information and only mention generally about what you are hearing.

Tech Minds: LoRa Text Chat with Two Othernet Dreamcatcher Boards

Back in the middle of last year we posted about Othernet's Dreamcatcher hardware and the LoRa chat application. The Dreamcatcher is Othernet's receiver and computing platform that is designed for receiving their satellite data broadcast. It is currently available for US$79.

Although the Othernet datacast is one way receive only, the Dreamcatcher board uses a LoRa radio chipset that has TX capabilities that can be leveraged for experimental purposes. One experimental piece of software that they developed is a chat application that works with two Dreamcatcher boards. It allows you to initiate a text based chat between two boards using the on board LoRa radio chips.

The TechMinds YouTube channel has recently released a video demonstrating the chat application in action, and the video shows how to set up, install and use it too. We note that since our post last year, the Dreamcatcher board has gone through a revision and no longer includes an LCD screen. The company name has also changed from "Outernet" to "Othernet".

What can you do with two Othernet Dreamcatcher Boards?

RTL-SDR and HackRF Used in Mr. Robot – A TV Drama About Hacking

A few readers have written in to let us know the role SDRs played in the last season of "Mr. Robot". The show which is available on Amazon Prime is about "Mr. Robot", a young cyber-security engineer by day and a vigilante hacker by night. The show has actual cyber security experts on the team, so whilst still embellished for drama, the hacks performed in the show are fairly accurate, at least when compared to other TV shows.

Spoilers of the technical SDR hacks performed in the show are described below, but no story is revealed.

In the recently aired season 4 episode 9, a character uses a smartphone running an SSH connection to connect to a HackRF running on a Raspberry Pi. The HackRF is then used to jam a garage door keyfob operating at 315 MHz, thus preventing people from leaving a parking lot. 

Shortly after she can be seen using the HackRF again with Simple IMSI Catcher. Presumably they were running a fake cellphone basestation as they use the IMSI information to try and determine someones phone number which leads to being able to hack their text messages. The SDR used in the fake basestation appears to have been a bladeRF.

HackRF Used on Mr Robot
HackRF Used on Mr Robot

In season 4 episode 4 GQRX and Audacity can be seen on screen being used to monitor a wiretap via rtl_tcp and an E4000 RTL-SDR dongle.

E4000 RTL-SDR Being used for Wiretap Monitoring
E4000 RTL-SDR Being used for Wiretap Monitoring

Did we miss any other instances of SDRs being used in the show? Or have you seen SDRs in use on other TV shows? Let us know in the comments.

Building a FossaSat-1 LoRa IoT Ground Station

FossaSat-1 is a recently launched open source "picosatellite" with an onboard LoRa repeater designed for Internet of Things (IoT) communications. It was launched via the Electron Rocket in New Zealand on December 6. At only 5 x 5 x 5cm in size and 250g in weight, a picosatellite is a tiny satellite that fits in your hand and can be affordably built and launched for around US$40k. 

Since the launch, it has been confirmed that FossaSat-1 was successfully launched, and is working correctly. However, the antennas have not properly deployed yet resulting in a weak signal that cannot be received by small ground stations. The team are currently working on getting the antenna manually deployed from earth and the latest updates can be found on their Twitter @FossaSys. They note that if the antennas cannot be deployed, then there is still the future launches of FossaSat-1B and FossaSat-2 to look forward to.

While waiting for the antennas to deploy you can watch Andreas Speiss' YouTube video where he explains the satellite in more detail, and shows how to build a FossaSat-1 ground station that can receive the FossaSat-1 LoRa transmission and upload it to the internet. While not SDR-related as it uses a hardware based LoRa chip, this is still an interesting project that some readers may be interested in.

We build a 20 Dollars LoRa Satellite Ground Station and we follow the FossaSat-1 launch

Passive Doppler Aircraft Scatter with a VOR Beacon and an RTL-SDR

Over on YouTube Meine Videokasetten has posted a video showing how he's been using an RTL-SDR to detect aircraft landing and taking off via the scatter on a VOR beacon. VOR (aka VHF Omnidirectional Range) is a navigational beacon that is transmitted between 108 MHz and 117.95 MHz from a site usually at an airport. Although as it is an older technology it is slowly being phased out in some places. 

An interesting observation can be made that is unrelated to the actual operation and use of VOR navigation. When an aircraft passes near the VOR beacon it results in the signal reflecting and scattering off the metal aircraft body. As the aircraft is moving quickly, it also results in a frequency doppler shift that can be seen on an RF waterfall display.

In his video Meine Videokasetten uses an RTL-SDR and OpenWebRX to receive the VOR signal. He then pipes the audio output of that signal into Speclab which allows him to get significantly increased FFT resolution for the waterfall. This increased resolution allows him to clearly see the doppler scattering effects of aircraft on the VOR transmission. He notes that it's possible from the scattering to determine if an aircraft is taking off or landing.

Passive doppler radar on VOR beacon transmitter .:°:. A let's test it out

We note that back in 2015 we posted about the ability to "fingerprint" aircraft using this technique. Different types of aircraft will result in unique patterns on the waterfall. In that post they used analogue TV carriers which are not very common in most countries anymore, so it's good to see that this can be used with VOR signals too.

Comparing large and small aircraft with aircraft scatter
Comparing large and small aircraft with aircraft scatter with an analogue TV transmitter. From previous post.