Tagged: rtl-sdr

RTL-SDR Now Runs on iPad M-Series Devices Directly via USB Without Jailbreak

Thank you to Arved (DK5AV/M0KDS) for writing in and sharing with us some exciting news. Arved has just announced his USBDriverKit extension for RTL-SDRs over on X and released it as open-source code on GitHub.

This is an unofficial port of librtlsdr, created using USBDriverKit instead of libusb, which is not available on iOS. This now allows RTL-SDRs to run directly on iPad iOS devices via USB without any jailbreak requirements. Previously, RTL-SDRs were unable to run on iOS devices directly. The only way around this was to run an RTL-SDR remotely and connect to it over a network via rtl_tcp.

The one caveat at this stage is that this currently only supports iPads with an M-Series SoC. At this time, only iPads use M-series chips, whereas iPhones currently use A-series chips. It also appears that the Blog V4 is not yet compatible with this driver due to the required EEPROM strings not being read by the drivers yet. 

In the video embedded below Arved shows an RTL-SDR running on his M1 iPad, and demonstrates CoronaSDR, welle.io, SatDump and rtl_tcp running.

RTL-SDR Running Directly on iPad via USB — Demo with CoronaSDR, welle.io, SatDump & rtl_tcp (no JB)

Arved has also released a video (embedded below), demonstrating SatDump connecting to an RTL-SDR and receiving a signal from a Meteor M2 LRPT weather satellite. He first records the IQ data with SatDump, then uses SatDump to decode the recorded data into an image.

Meteor-M2 4 LRPT Reception on iPad with RTL-SDR via USB — SatDump Demo

iq_tool: A Command Line Tool for Resampling, Filtering, Shifting and Correcting IQ Data Streams

Thank you to Eric Inloes for submitting to the blog his new tool called "iq_tool". This is a tool designed to "provide an easy, fast, and lightweight command-line utility for converting I/Q data from files or SDRs to a specific sample rate and format, and then either piping it to other programs or writing it to a file". Or in other words have a "neutral ffmpeg like converter tool but for IQ data".

Many SDR software tools are written for specific SDR hardware, such as RTL-SDRs, and may only accept a specific sample rate, type, or bit depth, meaning other SDRs cannot use these tools. The goal of iq_tool is to easily allow the IQ data stream from any SDR to be converted into a compatible format. 

Eric gives some examples. For example, if you wanted to use rtl_433 with an Airspy you could run the command:

iq_tool --input airspy  --airspy-gain-mode linearity --airspy-gain-value 15 --output stdout  --sdr-rf-freq 433.92e6 --output-sample-rate 250e3 --output-sample-format cu8 --output-agc | rtl_433 -r -

Similarly, for an SDRplay, you could run:

iq_tool --input sdrplay   --sdrplay-lna-state 15 --sdrplay-antenna b --sdrplay-if-gain -50 --output stdout  --sdr-rf-freq 433.92e6 --output-sample-rate 250e3 --output-sample-format cu8 --output-agc | rtl_433 -r -

We note that Eric released this tool with the caveat that it is experimental and was written with heavy AI assistance.

iq_tool example converting from a networked Airspy and piping into rtl_433
iq_tool example converting from a networked Airspy and piping into rtl_433

Further Tutorials on SatDump Map Projections

Thank you to Paul Maine, who has submitted to us two new SatDump tutorials that he has uploaded to his YouTube channel. These two tutorials follow on from his previous tutorials that we posted a month ago.

His SatDump V2.x Part 5 video demonstrates Recording and Processing. Paul shows his hardware setup and then shows GUI Live Processing, CLI Live Processing, CLI Recording and how to use the GUI to process recorded files.

E28 SatDump v2.x Part5 Recording & Processing

His SatDump V2.x Part 6 video on Projections introduces Map Projections. Paul uses things covered in earlier SatDump videos and builds upon them to create very interesting map projections. For his first example, he uses the Load First Party feature to download a GOES-19 CONUS image. Next, he shows how to add a shape file and a Severe Storms image expression. Lastly, he shows how to create an equirectangular map projection. In the video, Paul also shows how to create three other types of projections.

Before SatDump Projection
Before SatDump Projection
After SatDump Projection
After SatDump Projection
E29 SatDump v2.x Part 6 Projections

OpenWXSDR: A Streamlined Automated Multi-Sonde Decoder for Raspberry Pi with RTL-SDR or Airspy

Thank you to Mike (DL2MF) for writing in about the release of OpenWXSDR, a new open-source Python framework that turns one or more RTL-SDR dongles or Airspy SDRs into a fully automated radiosonde ground station running on a Raspberry Pi 4/5 or Linux x86 machine.

If you are unaware, a radiosonde is a lightweight instrument package typically carried by a weather balloon to collect atmospheric data, including temperature, humidity, pressure, and GPS position. It transmits this data back to the ground via radio signals. Using an RTL-SDR or another software-defined radio (SDR) along with appropriate decoding software, hobbyists or researchers can receive, decode, and visualize these signals. Radiosondes are typically launched by local meteorological agencies in many cities worldwide at least twice per day.

OpenWXSDR continuously scans the 400-406 MHz meteorological band, automatically identifies balloon transmissions using DFT correlation analysis, and spawns dedicated rs1729 decoder subprocesses. Supported sonde types include RS41, RS92, DFM06/09/17, M10, M20, iMet-54, LMS6, and MRZ.

The software also supports multi-sonde and multi-SDR. While one dongle scans for new signals, others simultaneously handle active decoding sessions. Decoded telemetry can be submitted in parallel to SondeHub v2 and to OpenWX.de via MQTT (with optional TLS), and as Horus-compatible UDP JSON datagrams for local tools like SondeMonitor. A built-in Flask and Leaflet web interface shows live positions, flight tracks up to 20,000 points, PTU sensor readings, and signal metrics, with most settings editable from the WebUI during operation.

OpenWXSDR Web Interface
OpenWXSDR Web Interface

No-SDR: A New Open Source Multi-User WebSDR for RTL-SDR

Thank you to George (gbozo), who has just released no-sdr (named from No(de)-sdr), a new open source multi-user WebSDR for the RTL-SDR written in Go and node JS. A WebSDR allows users to run an SDR remotely and access it over a local or internet network connection. This is useful for bringing an SDR closer to an antenna, instead of running a long, lossy coax cable, and for sharing SDRs among multiple networked users.

The no-SDR software runs on x86 or Raspberry Pi, is Dockerized, and supports multiple RTL-SDR dongles being connected at the same time. On the DSP side, it currently implements WFM (stereo + RDS), NFM, AM, AM Stereo (experimental stereo C-QUAM), USB, LSB, CW, and raw IQ, with digital decoders like ADS-B, AIS, APRS, POCSAG, FT8, and WSPR planned. There is also an "Identify Song" button that uses the Audd API to ID currently playing tracks on WFM, NFM, and AM.

George also points out that he's implemented an innovative lossless FFT codec with a very high ~10:1 compression ratio, as well as the Opus codec for audio. The result is a 12-15 kB/s transmission rate with a 12 FPS FFT with 8192 bins and AM demodulation compressed audio. 

The no-sdr Web Interface
The no-sdr Web Interface

sdrrat: An SDR receiver Terminal User Interface for RTL-SDR & HackRF

Thank you to qewer33, who has written in to share the release of his new Terminal User Interface (TUI) program for RTL-SDR and HackRF SDRs.  The program is called sdrrat, and it provides a complete TUI with FFT graph, waterfall spectrogram, VFO, and basic WBFM/NBFM/AM demodulation. 

qewer33 notes that the software is built with Rust, Ratatui, and FutureSDR and is completely free and open source. The code is available on GitHub.

sdrrate: TUI based SDR software for RTL-SDR and HackRF
sdrrate: TUI based SDR software for RTL-SDR and HackRF

Tracking Wildlife in South Africa with RTL-SDR And An Android App

Thank you to Gary Schneider from workingwithwildlife.org for writing in and submitting news about the release of his Android App called "SDR Direction Finder (RTL-SDR)" which currently costs US$9.99. Gary is a wildlife conservationist who has been using RTL-SDRs and his Android app to track animal beacons in the wild. Gary writes his story best:

I run a conservation project in South Africa conducting wildlife monitoring, and I’ve spent the past 7 years out in the field tracking wildlife. To make tracking more practical and affordable for researchers and NGOs, I’ve spent much of my time outside of fieldwork developing an Android app to replace traditional receivers, and I’ve recently published it on the Google Play Store.

While other apps exist, I’ve found them practically too difficult to use in field conditions and very limited in range. My focus was maximizing VHF range while keeping the interface simple.

By using the app’s custom IQ filter settings with an RTL-SDR V3 and LNA combo, my old spare Xiaomi phone now outperforms my $1,200 Comm Spec R-5000 receiver. The most challenging part of development was optimising the high-resolution waterfall to run smoothly at a high sample rate without any stuttering on low-end devices.

I added a built-in mapping feature to log bearings and automatically calculate estimated signal locations. The map also allows users to import their own custom KML/KMZ files. This has been incredibly helpful for me to quickly locate my tracked animals, and to subsequently export my data for further analysis. The waterfall makes it easy to handle signal drift or monitor multiple collars simultaneously (e.g. when I’m searching for a pack of African wild dogs which might have two or three working VHF collars fitted).

While wildlife tracking here is exclusively CW in the 148–152 MHz range, the app isn't limited to this. It also supports AM, NFM, WFM (Mono/Stereo), LSB, and USB across the full range.

Even though I developed this with wildlife tracking in mind, it should work equally well for falconry, fox hunting, or simply for general SDR enthusiasts.

The app is called "SDR Direction Finder (RTL-SDR)" on Google Play Store: https://play.google.com/store/apps/details?id=com.wildlifetracker.vhf

SDR Direction Finder (RTL-SDR) Screenshots
SDR Direction Finder (RTL-SDR) Screenshots

Spectrum SDR Android App Ported to iOS

Thank you to James Mainwaring of Knowle Consultants for submitting news about the release of an iOS port of his previously Android-only "Spectrum SDR" app for RTL-SDR. Knowle Consultants have previously released a range of RTL-SDR Android apps for FM, Airband, Ham FM and ADS-B reception. James writes:

As most people will be aware, it is not currently possible to connect an RTL-SDR dongle directly to an Apple mobile device. So the app is designed to be used with an instance of rtl_tcp running on a Mac, PC or maybe a raspberry pi.

It is also possible to install the app directly on an Apple Silicon Mac, so that is one with an M1, M2, ... etc. In that situation obviously rtl_tcp can be hosted on the same Mac too if needed.

Anyone needing help with this app or any of our existing Android SDR apps should contact [email protected]
 
For comparison, the Android version is available here:
 
Spectrum SDR iOS App Released