Tagged: rtl-sdr

Radio Field Mixed Reality Visualization with the Quest 3

The Meta Quest 3 is a recently released mixed reality headset from Meta. Recently Manahiyo has ported his RadioFieldAR software to the Quest 3. The RadioFieldAR software allows you to use a radio field probe together with an RTL-SDR or TinySA Ultra, and have the readings visualized in augmented/mixed reality. This could have several real world use cases, for example, probing an electronic PCB and mapping out the RF noisiest parts. Or for visualizing sources of RF signals.

Previously we posted about Manahiyo's work where he used a smartphone to visualize the augmented reality space, and also an older VR headset. Manahiyo writes:

MetaQUEST3, which was recently released, has a color pass-through function and features MR (Mixed Reality). Thanks to this, this software was made possible.

With a smartphone, We took measurements while looking at the antenna through the display, but with QUEST3, we can take measurements in MR (Mixed Reality) using color pass-through features.

In addition, the hand tracking function allows various settings and FFT to be displayed.

It is now possible to take measurements in a more natural and comfortable way.

There are still many bugs, so I'm considering distributing the executable file as before after fixing them.

Manahiyo has not released the software yet, but it appears he is willing to personally distribute the software for testing first. If we receive any further details about software  distribution we will update this post.

UPDATE 29 November 2023: Manahiyo has released the software on Github. He notes:

This software now supports both RTL-SDR and tinySA-ULTRA. Of course, Quest3 is also required. I have provided instructions in the README.md on the GitHub page, which should help you understand how to use it. Currently, only the APK file is available for download. I do not have a plan to open the source code at this time.

RadioFieldMR with QUEST3 -Measuring noise on FPGA board-

RadioFieldMR with QUEST3 -Measuring the FM transmitter signal-

RTL-SDR Blog V4 Dongle + Antenna Set Back in Stock

This is just a quick post to let people who have been waiting know that the RTL-SDR Blog V4 Dongle with Multipurpose Dipole Antenna set is back in stock in our international store which ships from China.

Amazon stocking has been slightly delayed, but the ship with the stock should be on the way soon, and we expect it to be stocked within about four weeks. 

The V4 dongle can be ordered from our store at www.rtl-sdr.com/store.

Also see our release post and V4 users guide pages for more information about the RTL-SDR Blog V4.

Please remember that not all software is compatible with the RTL-SDR Blog V4 yet. The majority of programs on Windows and Linux are already compatible, or just require a simple driver swap, but some programs on MacOS will need more time to update because on these platforms the drivers are bundled with software. Android has recently seen the SDR Driver app updated to support the majority of Android apps.

Please consult the V4 users guide for the latest information about software compatibility and how to update the drivers.

SatDump Projections Improved

SatDump is a popular program that is used with RTL-SDRs and other SDRs for decoding transmissions from a wide array of weather satellites and their various imagers and sensors. Recently SatDump's author @aang254 has been working on improving the way projections work. Projections are essentially when the weather satellite image is stretched and skewed to fit correctly over the curved earth.

This means now that city markings and border lines should show up in the correct placed in any images received from SatDump.

If you're interested @aang254 has uploaded blog post on the SatDump website explaining the math, algorithms and problems he found when trying to get projections done right.

SatDump now has accurate projections

Repurposing a Wireless networking Dish for L-Band HRPT Satellite Reception

Over on his YouTube channel, "saveitforparts" has uploaded a video showing how he's modified an old wireless networking dish for L-band HRPT satellite reception. L-band satellites that transmit HRPT are polar orbiting, meaning that some sort of tracking solution is required to point the satellite dish at the sky as the satellite passes over. However, lacking any sort of motorized solution, saveitforparts simply removes the dish mount so that the dish can be manually held and tracked.

He notes that he uses the paid version of the Stellarium app for augmented reality tracking of the satellite. In the past there was a great app called "Satellite AR" which did this for free, however within the past few years it has unfortunately been removed from the Google Play store.

The modifications to the dish involve removing the feed from the satellite and installing a custom built helical feed. He also uses a small handheld PC with RTL-SDR on the rear. However in the end the handheld PC turns out to be problematic so he switches to a laptop.

The dish used in saveitforpart's project is quite similar to our upcoming Discovery Dish crowd funding project, so please check that out if you are interested.

Handheld Cyberdeck Dish For Live Satellite Data

Manuel Tests the RTL-SDR Blog V4 on SDRuno

In one of his latest YouTube videos, Manuel Lausmann has been testing the RTL-SDR Blog V4 on SDRuno. SDRuno is the official software for SDRplay RSP devices, however, they provide an ExtIO interface which allows it to be used with an SDR that has an ExtIO driver.

The RTL-SDR Blog V4 recently got an ExtIO driver via hayguen's latest ExtIO release at https://github.com/hayguen/ExtIO_RTL/releases.

In the video Manuel shows how to download and copy over the ExtIO dll, and how to select it in SDRuno. He then goes on to show it in action receiving some HF signals. Note that Manuel's video is narrated in German, but you can use YouTubes auto-caption and auto-translate features to get English subtitles.

RTLSDR Blog V4 mit SDRUNO

Raspberry Pi 4 USB Bug Experienced with RTL-SDRs now Fixed with Kernel Update

Thank you to Michael B for letting us know about recent fixes to the Raspberry Pi kernel which affect RTL-SDR users. If you've been experiencing error "rtlsdr_read_reg failed with -7" when running RTL-SDR software on Raspberry Pi 4's running a Linux kernel with version 6.1 or higher, a Raspberry Pi kernel fix has been pushed which should fix the problem.

This problem "rtlsdr_read_reg failed with -7" appears to occur after having closed any program that uses an RTL-SDR, and then reopening it.

This doesn't seem to have been an issue for the older 5.12 and 4.19 kernels where this issue was previously fixed, but Raspberry Pi recently moved to the 6.1 kernel in May 2023 where the issue came back. Raspbian releases after this date may have been problematic.

The official Raspbian should eventually update, but if you've been experiencing this issue, you could try update your kernel now using:

sudo apt install rpi-update
sudo rpi-update

Alternatively according to Michael, kernel version 6.6.y should also have this problem fixed:

sudo rpi-update rpi-6.6.y

Note that updating the kernel could break other software, so doing this is at your own risk.

Wok-The-Hydrogen: A Low Cost Wok Based Hydrogen Line Radio Telescope

In addition to the last Hydrogen Line radio astronomy post from a few minutes ago, we've also recently seen a post on Hackaday about a research paper (PDF) that describes a Hydrogen Line Radio Telescope made from a cooking Wok, LNA and RTL-SDR dongle.

In the paper Leo W.H. Fung et al of Hong Kong University of Science and Technology uses a 61cm cooking Wok with a custom made dipole feed at the calculated focal point. A filtered LNA sits after the feed, and is connected to an RTL-SDR Blog V3 dongle enclosed within a metal cookie box for additional shielding.

The results show that the Hydrogen Line was indeed detected, and measurements of the galactic rotational velocity were possible.

Again we note that we will soon by crowdfunding for a product called the 'Discovery Dish' that will be fairly similar in size and shape. It is designed for receiving L-band weather satellites, but can also be used as a Hydrogen Line telescope too.

The Wok Hydrogen Line Telescope Setup

TechMinds: Demonstrating OpenWebRX Plus

In one of his videos from a few days ago Matt from the Tech Minds YouTube channel tests out OpenWebRX+, an unofficial fork of OpenWebRX. OpenWebRX is open source software which enables users to put software defined radios like RTL-SDRs on the internet, allowing people from all over the world to access the receiver if desired, or just letting yourself access it remotely if you want to keep it private.

OpenWebRX+ adds several additional decoders and features on top of the official version. In the video Matt demonstrates OpenWebRX+ running on a Raspberry Pi 4, with an SDRPlay RSPdx. He demonstrates the web GUI in action and shows decoding examples of the various decoders that OpenWebRX+ comes with.

OpenWebRX Plus - The ULTIMATE Web SDR Application