Tagged: android

SignalID: Shazam Style Automatic Signal Identification for Android

SignalID is a new Android app available on the Google Play store which offers Shazam-like radio signal identification. Just like Shazam does for music, you simply tune to an unknown signal with your SDR, play the raw audio, and let the app listen to it for five seconds. It then computes an audio fingerprint and checks to see if it knows what the signal is. 

We tested the app but unfortunately we were unable to get it to detect any signals. Please write in the comments if you have success. As it uses audio fingerprinting, the app is probably highly dependant on choosing the correct demodulator (AM/FM/SSB etc), and also the tuning and signal quality. We note that most of the signal sources seem to come from our sister site the Signal ID Wiki. Searching through the wiki is a good alternative if automated solutions fail.

However the the app is new and we expect improvements and more signals to be added in the future. Currently the following signals can be recognized: 

- RTTY (Commercial 85Hz, 170Hz, 450Hz, 850Hz, Amateur 170Hz)
- PactorI (Standard, FSP, FEC, SELCALL)
- ASCII (170Hz)
- ALIS
- Codan8580 (200Hz, 250Hz)
- CIS36_50
- CIS40_5
- CIS50_50
- STANAG 4285 (GEN, SYS3000 FEC, 8PSK, TFC, IDLE, SYS3000)
- FT4

- FT8
- WEFAX (120, 240)
- 2G ALE
- 3G ALE
- CHIP64
- APRS (Burst)
- ATIS
- Tetrapol
- POCSAG
- FLEX (2FSK)
- PSK (31, 63, 125, 250, 500)

We note that this app reminds us of a Python based signal identification app for the PC called "audio_recognition_system" which we posted about earlier this year.

SignalID: Shazam-like audio based signal identification for Android.

SignalID - Demonstration

Trump Tweets about Pushed Buffalo Protestor Scanning to Jam Police Radios with an RTL-SDR and Android Phone

In political news 75 year old Buffalo protestor Martin Gugino has been generating controversy due to a video of him being pushed to the ground by a police officer, then subsequently lying motionless while bleeding from the head and being ignored by other officers.

Recently US president Donald Trump tweeted about a video news report by "One America News" (OAN) indicating that Gugino may have been trying to scan police with a "capture scanner". Whilst talking about the capture scanner they show an image of an RTL-SDR dongle and Android phone running the SDR Touch software. OAN go on to say that these capture scanners are designed to "skim microphones" in order to capture police communications, and are a tool commonly used by Antifa. Credit to @hackerfantastic for initially tweeting about the RTL-SDR being featured in the video.

Trump's tweet reads "Buffalo protester shoved by Police could be an ANTIFA provocateur. 75 year old Martin Gugino was pushed away after appearing to scan police communications in order to black out the equipment @OANN
I watched, he fell harder than was pushed. Was aiming scanner. Could be a set up?".

We're not entirely sure where this theory from OAN came from as there is no need to get so close in order to listen to police radio communications, since if unencrypted, they can be listened to from anywhere in the city. It's also unclear as to what microphones police would be using, and how these could be "skimmed" with an RTL-SDR. As for blacking out the equipment, an RTL-SDR cannot transmit so it would be impossible to use to jam the radios. An illegal jammer could be used after scanning, but police frequencies are already well known anyway, and there would be no need to scan for them so close even if low power comm links were used.

The video also shows that he appears to be filming police badge numbers with his phone before he was pushed, so it is unlikely that he was using an RTL-SDR and running SDR Touch at the same time as the camera app. No cables, antenna or dongle can be seen in the video either.

In the past we have seen a Slovenian researcher almost jailed for performing University research with an RTL-SDR, and a UN expert arrested for possessing an RTL-SDR in Tunisia. So this is a timely reminder to be careful as police and media do not always understand what an SDR is.

EDIT: Please note that this is not a political post or blog. We only post it to highlight the severe lack of understanding that can surround SDR and our technical hobbies. Comments inciting violence against protestors or anyone are NOT OK, and will be removed. Please keep discussions technical and civil in nature.

OAN indicates that Martin Gugino may have used an RTL-SDR on police
OAN indicates that Martin Gugino may have used an RTL-SDR "capture scanner" on police

GNU Radio Code for Android Now Released

Back in November 2019 we posted how Bastian Bloessl (@bastibl) had teased us with his ability to get GNU Radio running on an Android phone. Now he has officially released his code to the public on GitHub. This is quite a remarkable development as you can now carry a full DSP processing suite in your pocket. In addition to the code, he's put up a short blog post explaining a bit about the port. He notes some highlights of the release:

  • Supports the most recent version of GNU Radio (v3.8).
  • Supports 32-bit and 64-bit ARM architectures (i.e., armeabi-v7a and arm64-v8a).
  • Supports popular hardware frontends (RTL-SDR, HackRF, and Ettus B2XX). Others can be added if there is interest.
  • Supports interfacing Android hardware (mic, speaker, accelerometer, …) through gr-grand.
  • Does not require to root the device.
  • All signal processing happens in C++ domain.
  • Provides various means to interact with a flowgraph from Java-domain (e.g., Control Port, PMTs, ZeroMQ, TCP/UDP).
  • Comes with a custom GNU Radio double-mapped circular buffer implementation, using Android shared memory.
  • Benefits from SIMD extensions through VOLK and comes with a profiling app for Android.
  • Benefits from OpenCL through gr-clenabled.
  • Includes an Android app to benchmark GNU Radio runtime, VOLK, and OpenCL.
  • Includes example applications for WLAN and FM.

He's even included demonstration code that turns a USRP B200 SDR connected to an Android phone into a WLAN transceiver which can run in real time on faster devices.

Installing it may not be easy for most, but Bastian has included full build instructions on the GitHub page, and makes use of a Docker file which should simplify the installation a bit.

GNU Radio running on an Android phone, usinga USRP B200 SDR as a WLAN transceiver.
GNU Radio running on an Android phone, usinga USRP B200 SDR as a WLAN transceiver.

GNU Radio 3.8 on un-rooted Android receiving FM w/ HackRF (take 2)

Radwave Updates: Browse SETI Spectrum Data on your Android Device

Back in February 2019 we first posted about Radwave, an Android SDR App for RTL-SDR dongles. It has some interesting features not found in other Apps like the ability to easily zoom, pause and rewind the spectrum at any time.

The author has decided to make use of these spectrum browsing enhancements by providing access to full SETI (Search for Extraterrestrial Intelligence) spectrum data sets which can be browsed via the app for a small fee. From a post on our forums the author of Radwave writes:

I've been developing Radwave, which is an RTL-SDR Android app for exploring the spectrum. I recently added some new functionality, allowing users to interactively explore full resolution SETI data hosted in the cloud - no SDR needed. You can see a preview of it here https://youtu.be/8ZJFzKcWejA and download it from https://play.google.com/store/apps/deta ... ve.android

This data comes from Breakthrough Listen. These datasets are quite large, and Radwave does all the bulk downloading, processing and hosting of the datasets, allowing you to easily navigate your way through the spectrum. If you find something cool, you can tag it and share it.

Currently there are three datasets available in the first bundle ($10 USD): Voyager 1 and two 'Oumuamua collections (surveys of the the first observed interstellar object in our solar system). The data is big, and is hosted in AWS. That gets pricey, so I'll be adding more collections to this first bundle as funding permits. If there are certain datasets you're interested in seeing, definitely let me know.

 

radwave intro 20200225

Combining Android Tasker and an RTL-SDR for Mobile Automated Frequency Power Scans

Over on YouTube Ian Grody has uploaded two videos demonstrating an early alpha project that he is working on which combines Android Tasker with RTL-SDR frequency scanning. Tasker is an Android automation app which allows users to define a task based on a context. For example, you could set it to turn on WiFi and open an app (task) every time you arrive at a certain location (context).

Ian's idea is to create a Tasker application that performs an rtl_power scan with the RTL-SDR whenever a certain context is detected. The current version of his Tasker app can perform an rtl_power scan over a certain frequency range at the tap of a button, detect the strongest frequencies in that range, and plot a marker at the current location on a Google map which displays the strongest frequency detected at that location. He eventually hopes to turn the application into a wardriving application that will scan 27 MHz - 1.7 GHz for active signals while on the move.

His Tasker alpha application is available via the link on his Reddit post.

Tasker and a Software Defined Radio

Tasker and an RTL SDR - Part II

Preview: GNU Radio 3.8 Running on an Un-Rooted Android Smartphone

Over on Twitter and YouTube Bastian Bloessl (@bastibl) have been posting teaser shots and videos of GNU Radio 3.8 running on an un-rooted Android device. Unfortunately there doesn't yet seem to be any word yet on how he's been able to do this, but we guess  that the details will all be released in due time, possibly on his blog.

GNU Radio is an open source digital signal processing (DSP) toolkit which is often used in cutting edge radio applications and research, and to implement decoders, demodulators and various other SDR algorithms.

GNU Radio 3.8 on un-rooted Android receiving FM w/ HackRF (take 2)

Dash Mounted ADS-B With an RTL-SDR Blog V3

Reddit user [Bobcalamarie] recently [posted] about how he uses his car dash mounted Android tablet along with an RTL-SDR Blog V3 and a magnetic mount antenna while sitting in traffic to track aircraft overhead.

We’ve seen something similar to this once before when [Signals Everywhere] uploaded a video showing off ADS-B reception (among other things) to a dash-mounted Windows tablet and an Android head unit.

The software used by Bobcalamarie is the Android [Avare ADS-B] software which can be found in the Google Play Store. However, other applications exist for Windows, Linux, and other operating systems as well. Some software such as [Virtual Radar Server] even allows you to set-up alerts for specific types of aircraft. Which while we wouldn’t condone it, it might come in handy for someone in traffic.

What would you do if you had an SDR installed in your vehicle? We would love to hear what you have to say in the comments below.

Dash Mounted ADS-B Reception

Radwave Beta: Android RTL-SDR RF Analyzer App with Spectrum Pause and Rewind Features

Radwave Screenshot
Radwave Screenshot

Radwave is a recently released Android App for RTL-SDR dongles. It provides a real time waterfall of the RF spectrum, and it's defining feature is that you can easily zoom, pause and rewind the spectrum at any time. The software is currently in beta, and doesn't demodulate any signals, but the work and ideas behind the spectrum display features is really interesting.

Radwave utilizes RTL-SDR dongles and the RTL2832U driver app to allow people to interactively explore the RF spectrum. You can dynamically zoom in and out in time and frequency, pause, and go back in time - all without losing any samples. If you find something cool, tag it and share with friends.

Radwave core technology is its interactive real-time spectrogram. It shows all the spectrum - utilizing every sample1 - for the entire collection2. Frequencies are aligned over time as you change the RF center frequency3, helping you make sense of what you see.

1 Adjacent non-overlapping DFT windows

2 Up to device limitations

3 Alignment limited by buffer uncertainty

Radwave Intro - We're in Beta!