Category: RTL-SDR

rtl_haos: An rtl_433 to Home Assistant Bridge

Thank you to Jaron McDaniel for writing in and sharing with us the release of his open source software called "rtl_haos". rtl_haos is a 'drop-in' bridge that turns one or more RTL-SDR dongles into Home Assistant friendly sensors via rtl_433 and MQTT. Jaron writes:

I just finished a tool that that bridges data received from rtl_433 into Home Assistant friendly entities. Basically allowing you to integrate anything rtl_433 can see into Home Assistant.

Basically you clone the git to a Rasberry PI, configure it for your MQTT server, plug in a RTL-SDR or two and you'll see entities with icons and units automatically assigned to whatever rtl_433 discovers.

This tool allows you to connect older and cheap non-Wi-Fi connected sensors to Home Assistant, which typically communicate to a base station via wireless ISM band signals. Home Assistant is an open-source home automation platform that integrates and controls household devices such as lights, sensors, and actuators.

rtl_haos Overview
rtl_haos Overview

Frugal Radio: Using a 25 Dollar PC for Decoding with SDRs

Over on YouTube, Rob from the Frugal Radio channel has uploaded a video showing that you don't need to shell out thousands for a capable PC to run your SDR. Robs finds five second-hand Dell Optiplex 9020 PCs advertised for just $25 each, and shows how each PC is powerful enough to run multiple SDR decoders at once, and run three monitors.

He notes that these PCs are a bargain as they come with a 4th gen Intel i5, 8GB RAM, and a 256 GB SSD. And they even come with Windows 10 Professional pre-installed.

Later in the video Rob shows what each of his $25 PCs is doing. He shows how PC1 decodes five digital trunk systems with RTL-SDRs and runs SDR++ with an Airspy. And how PC2 decodes P25 trunk systems and runs the PDW pager decoder.

Rob notes that deals on these second-hand Dell Optiplex 9020 PCs are easy to find on eBay as these are common ex-corporate PCs.

25 dollar 24/7 SDR PCs for the Shack

An Overview of 2025 SDR Black Friday Deals

Below, we're collating the best Black Friday sales we could find on SDR and related products.

If you find any other good sales for SDR or related products, please post in the comments!

RTL-SDR Blog

We're currently offering $5 of V3 dongles (including the V3c) on Amazon. The sale will last until Monday 1 December, and only while stocks last.

RTL-SDR Blog V3 Dongle + Antenna Kit: US$47.95 US$42.95 (Link)
RTL-SDR Blog V3 Dongle Only: US$37.95 US$32.95 (Link)
RTL-SDR Blog V3c Dongle Only: US$39.95 US$34.95 (Link)

We also want to add that in December, the price of V4 dongles will be raised, due to rising chip costs, and dwindling R828D stockpiles, so buying now is purchasing while essentially on sale.

We're also participating in the Airspy 25% sale with the YouLoop listing on our store. The sale takes the price down from $39.95 to $29.96.

Airspy

Airspy offers low-cost RX-only SDRs. Airspy is holding a 25% off Black Friday sale. Black Friday is usually their biggest discount of the year. The sale is offered by their official iTead store and by most resellers. Links to their sales are platforms available here https://airspy.com/purchase

Airspy R2: US$169.00 $126.75
Airspy Mini: US$99.00 US$74.25
Airspy HF+ Discovery: US$169.00 US$126.75
Airspy SpyVerter R2: US$49.00 US$36.75

SDRPlay

SDRplay offers low-cost RX-only SDRs. There do not appear to be any direct Black Friday deals from SDRplay, but on Ham Radio Outlet, the SDRplay nRSP-ST and DUO units are on sale. The RSPdx-R2 and RSP1B appear not to be on sale.

SDRplay nRSP-ST: $499.95 $399.95
SDRplay DUO: $299.95 $249.95

FlexRadio

FlexRadio offers high-end SDRs aimed at ham radio users. They are currently running a Black Friday deal as shown in the screenshot. https://www.flexradio.com/products/categories/black-friday/

Ham Radio Prep Course

While not physical SDRs, some people interested in getting their amateur radio licence in the US may be interested in this study course, which is discounted for Black Friday. https://hamradioprep.com/black-friday

They have various course bundles on sale, but this screenshot is of the full bundle.

halow_scanner: An RTL-SDR Based 802.11aH HaLow Channel Scanner

Over on GitHub we've recently noticed the release of halow_scanner, a Python script that uses an RTL-SDR to scan the 802.11ah (WiFi HaLow) channels in the sub-GHz spectrum to determined which channels have the least noise/interference.

Unlike standard WiFi, which operates outside of the RTL-SDRs range at 2.4 GHz+, 802.11ah operates in the sub-GHz ISM bands, which RTL-SDRs can easily receive.

Use of these lower frequencies gives 802.11ah HaLow excellent signal penetration, making it useful for long-range, low-power IoT devices. With 802.11ah HaLow links, several kilometers can be achieved.

The software's features include:

  • 🔍 Scans all 802.11ah HaLow channels in the US 902-928 MHz band
  • 📊 Supports multiple channel bandwidths: 1, 2, 4, and 8 MHz
  • 📡 Uses RTL-SDR for spectrum analysis
  • 🎯 Identifies the cleanest channel with lowest noise floor
  • 📈 Provides detailed power spectrum measurements
  • ⚡ Fast scanning with averaging for accuracy
Comparison Between regular WiFi and 802.11ah HaLow. Source: https://www.gateworks.com/802-11ah-halow-long-range-low-power-wireless-for-iot/
Comparison Between regular WiFi and 802.11ah HaLow. Source: https://www.gateworks.com/802-11ah-halow-long-range-low-power-wireless-for-iot
 

Software Defined Toolkit: A DIY Radio Reconnaissance Device with RTL-SDR and EvilCrow RF Inside

Thank you to "p3rp0ul" for writing in and sharing his neat-looking build of a "Software Defined Toolkit," which consists of two RTL-SDRs, EvilCrow RF, and other RF signal conditioning hardware, all in a ruggedized metal enclosure. He writes:

It’s a compact, field-ready SDR platform that consolidates two RTL-SDR receivers (one acquired via your site), a GPS timing/position module, an LNA with adjustable biasing, and an integrated ESP32-based ISM-band transceiver subsystem into a single rugged enclosure. The project explores how far low-cost SDR hardware can be pushed when carefully packaged, powered, filtered, and shielded as a coherent tool rather than a loose bench setup.

The design focuses on field usability: modular power distribution, fully externalized RF and antenna connectivity, thermal management for the dongles, and internal coax routing optimized with ferrite suppression. The addition of the ESP32 subsystem brings replay, sniffing, jamming, and remote-operation capabilities, extending the utility of RTL-SDR hardware in practical RF reconnaissance and experimentation.

P3rp0ul has shared full details about his build on both Hackaday.io and Hackster.io.

P3rp0ul's DIY Software Defined Toolkit
P3rp0ul's DIY Software Defined Toolkit
Inside the Enclosure
Inside the Enclosure

Talking Sasquach Reviews the uConsole and RTL-SDR Antenna Board Expansion

The uConsole is a portable computer system based on the Raspberry Pi CM5 module. It adds a screen, battery, and complete hardware keyboard with a mouse trackball to the CM5, while allowing for various expansion boards.

One such expansion board of interest to us is the RTL-SDR AIO V2 module, which adds an RTL-SDR, as well as adding capabilities such as LoRa, GPS, RTC, USB Hub, USB 3.0, and RJ45 Ethernet. We currently have one on order for our own review, but it is currently in pre-order status, and the V1 module has been out of stock for a long time.

Over on YouTube, Talking Sasquatch has managed to get his hands on one and has created a video about it. In the video, he shows the assembly of the uConsole and RTL-SDR AIO and how to flash the DragonOS Linux distribution, which contains many pre-installed RTL-SDR programs.

He goes on to show the system running SDR++ and receiving an FM station, as well as showing how it can connect with a Flipper Zero.

This uConsole HACK is a Game Changer

Creating a Homemade Portable Raspberry Pi Based RTL-SDR System

Thank you to Giuseppe (IT9YBG) for writing in and sharing with us his homemade portable RTL-SDR system made out of a Raspberry Pi 3, RTL-SDR Blog V3, 5-inch LCD screen, and a Bluetooth keyboard. Giuseppe notes that when running the system from a cell phone power bank, he only got about an hour's worth of battery life. So instead, he runs it from his motorcycle starter battery, which gives a much longer usable battery life.

Of course, if you wanted a more turn-key portable RTL-SDR system, you could look into the Vivid Unit GPSDR (which we reviewed here), or the AIO V2 module for the uConsole.

Giuseppe's Portable RTL-SDR System
Giuseppe's Portable RTL-SDR System

Tech Minds: A Review of the Vivid Unit with GPSDR RTL-SDR Module

The Vivid Unit is a single-board computer with a built-in LCD touch screen. There is an optional module called the "GPSDR," which is an RTL-SDR, upconverter, and GPSDO module that, when combined with the Vivid Unit, creates a handheld, portable SDR.  Last month, we reviewed the Vivid Unit and its "GPSDR" RTL-SDR add-on module on our blog.

Recently, Matt from the Tech Minds YouTube channel has also uploaded a review video of the Vivid Unit and GPSDR. In the video, Matt shows the hardware and demonstrates it in action, receiving various signals, including ADS-B and HF signals. He notes that he gets a good reception on HF even with just a telescopic antenna; however, the built-in speaker is tinny, and better audio is obtained by connecting it to a Bluetooth speaker. Matt also tests rtl_433, confirming that other RTL-SDR software works on the Vivid Unit too.

Matt also notes that you can use the code "TECHMINDS" if ordering from the UUGear site directly, and you'll get 5 Euros off each GPSDR that you order.

GPS Assisted RTL-SDR For The Vivid Unit - Runs Debian 11!