Category: RTL-SDR

calcRadio: A Casio FX-CG20 Calculator Front End Interface for RTL-SDR

In the past, RTL-SDR.COM reader JJ has shared with us his LegoPi project, which demonstrated a clever way to enclose a self-contained RTL-SDR build, as well as his multi-feature living room radio build, which combined an RTL-SDR for live radio and an internet-based radio system with MP3 player.

Recently, he submitted to us a new project called 'calcRadio' (information about the calcRadio can be found at the end of the linked page). The calcRadio project consists of a similar self-contained RTL-SDR build as seen in his previous projects (RTL-SDR with speakers and a single-board computer), but this time, it's controlled via an old Casio FX-CG20 calculator. The calculator's interface is programmed in C, and JJ has uploaded his open source code on GitHub.

JJ writes:

The front-end is made of an older CASIO calculator, the fx-CG20, which can be programmed in C thanks to the non-official CASIO SDK: https://github.com/Jonimoose/libfxcg/releases (the fx-CG20 built-in basic language was way too slow).

The back-end is same as last build, a Strong SRT 2023 TV box, flashed with Armbian + Ubuntu and a bash script to handle everything. Under Linux, the Android board is known as Amlogic Meson GXL (S905X) P212 Development Board. It has about the same CPU power as a Raspberry Pi 3 Model B+ but with less power consumption, built-in storage and infrared port.

The key to make it work was the presence of a cloning port on the calculator, which was connected to the UART port on the Android board, allowing serial communication to be established.

The calcRadio build

An RTL-SDR/LoRa/GPS/RTC/USB-Hub Extension Board for the uConsole

The uConsole is a handheld computing device developed by ClockworkdPi that costs US$189. Its computing power is based on a Raspberry Pi Compute Module 4, but other CPU options are also available. The uConsole comes with a 5-inch 1280x720 HD screen, keyboard, and battery module that takes two 18650 lithium-ion batteries.

The uConsole is also modular, allowing for expansion. We wanted to thank RTL-SDR.COM reader Sunny for sharing the news that a RTL-SDR/LoRa/GPS/RTC/USB Hub All-In-One Extension Board for the uConsole will be available from HackerGadgets soon. This board includes a full RTL-SDR module, an SX1262 LoRa chip, a GNSS chip, a real-time clock chip, and a USB hub. The expansion board is currently advertised as being priced at US$78.99.

The expansion board is not yet available for sale, but you can join their waiting list to be notified of its release.

Over on YouTube 'Symbiiote' has released an early review video showing how to build the module into the uConsole and then showing it running SDR++ and receiving some broadcast FM stations.

This uConsole accessory changes EVERYTHING!

A Handheld Cyberdeck with RTL-SDR

Over on his YouTube channel and Hackaday.io blog page, Nicholas LaBonte has shown his "Cyberdeck Handheld" which is a portable computer consisting of a Raspberry Pi 5, LCD screen, custom CNC'd keyboard, UPS module, and an RTL-SDR. All the components are placed in an aesthetically pleasing custom enclosure, made of some interesting premium materials like Sepele hardwood and Richlite. Nicholas writes:

Having been inspired by the uConsole and similar projects, I wanted to try my hand at building my own with off-the-shelf components. Richlite and Sepele hardwood would be used for the housing, materials that I have worked with furnishing yacht interiors. Combined with a bronze heatsink, I wanted to merge cyberpunk and nautical aesthetics. Since the keyboard was the biggest challenge, I started there by combining concepts from both Bobricius and the Ello 2M keyboards, settling on tabbed keys atop PCB-mounted microswitches.

Cyberdeck Handheld

TechMinds: Building a DIY Standalone SDR with a Raspberry Pi, 5-Inch TouchScreen, SDRplay RSPdx and the PiHPSDR Software

Over on the TechMinds YouTube channel, Matt has uploaded a video showing how he created a DIY standalone SDR using an Elecrow 5-inch touchscreen display, Raspberry Pi 5 and an SDRplay RSPdx. The software he uses is PiHPSDR, which is compatible with the SDRplay and RTL-SDR dongles.

In the video, Matt shows how to set up the hardware, the Raspberry Pi OS, and the required software and drivers. He then shows the setup running PiHPSDR and the various settings and features available in the software.

Could This Be The BEST SDR Receiver? Using PiHPSDR & SDRPlay RSPdx

Khanfar Spectrum Analyzer: Signal Analysis Tools for the RTL-SDR

Thank you to M. Khanfar for submitting news about the release of his new spectrum analyzer, sweeper, and FM Radio demodulator tools for the RTL-SDR. The tools are freely released, however, they do not seem to be open source.

THIRD PARTY SOFTWARE VIRUS WARNING: We just want to note that Khanfar's software shows a few positive results for viruses on VirusTotal. These are most likely false positives, but please use this software at your own risk, especially as it is not open source.

The first tool M. Khanfar is releasing is the Khanfar Full Spectrum RTL-SDR Sweeper tool, a wideband spectrum analyzer for the RTL-SDR. It allows the RTL-SDR to produce a spectrum sweep over a large bandwidth by rapidly re-tuning the frequency and plotting each 2.4 MHz live sweep sequentially. This is the same concept used by previous tools like rtl_power and Spektrum.

Khanfar RTL-SDR Sweeper
Khanfar RTL-SDR Sweeper

The second tool released is the Khanfar Advanced Spectrum Analyzer. This tool allows you to view the live spectrum from an RTL-SDR in various visualization modes.

Khanfar Spectrum Analyzer
Khanfar Spectrum Analyzer

The third tool is Khanfar-FM-Radio, a text-based wideband and narrowband FM demodulator for the RTL-SDR.

Khanfar WFM-NFM Demodulator
Khanfar WFM-NFM Demodulator

M. Khanfar notes that all tools can open multiple instances of themselves, allowing them to be used use multiple RTL-SDR dongles on the same machine.

In the video embedded below, M. Khanfar shows his three software applications in action.

Khanfar Spectrum Analyzer

A 3D Printed V-Dipole Guide for the RTL-SDR Blog Dipole Kit

Thank you to Denis for submitting his 3D printable V-dipole guide for our RTL-SDR Blog Dipole Antenna set. The guide holes the dipole at a 120-degree V-shape angle, which is ideal for receiving polar-orbiting satellites such as NOAA and Meteor at 137 MHz. 

Back in 2017, Adam 9A4QV wrote about how a V-Dipole could be used as a very simple yet effective antenna for receiving weather satellites. Since then, it has become a popular beginner's choice for receiving weather satellites.

In the past, we've also seen other 3D-printed V-dipole holders, such as this one by f16v1per. However, f16v1per relies on cable ties to hold the elements in place, whereas the design by Denis simply slides in place.

If you don't have an RTL-SDR Blog Dipole Antenna, you can also build a V-dipole out of an electrical terminal block and a different 3D-printed part, as shown in this previous post.

3D Printed V-Dipole Holder
3D Printed V-Dipole Holder

Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites

Over on the saveitforparts YouTube channel, Gabe has uploaded a video showing how he uses WebSDR streams to show how Russians, including Russian soldiers, are using old US Military satellites for long-range communications around Ukraine.

In the '70s and '80s, the US government launched a fleet of satellites called "FLTSATCOM," which were simple radio repeaters up in geostationary orbit. This allowed the US military to easily communicate with each other worldwide. However, the technology of the time could not support encryption or secure access. So security relied entirely on only the US military's technological superiority of being the only one to have radio equipment that could reach the 243 - 270 MHz frequencies in use by these satellites. Of course, as time progressed, equipment that could reach higher frequencies became commonplace.

In the video, Gabe explains how many Russian soldiers involved in the Ukraine war are using these legacy satellites to communicate with each other. He notes that apart from voice comms, some channels are simply Russian propaganda and music, as well as some channels that appear to be jammed. Gabe also notes that the "UHF Follow-On Satellite" (UFO) satellites that were launched as recently as 2003 are also being hijacked, as they also have no encryption or secure access.

In the past, we also posted a previous video by Gabe about attempting to receive these satellites from his home in North America. However, on that side of the world, the satellites are being hijacked by Brazilian pirates instead.

Russia Is Hijacking US Military Satellites

Skies-ADSB Updated to V2.0.3

Back in 2022, we first posted about the release of skies-adsb, a browser-based app that uses ADS-B data from an RTL-SDR to provide a 3D view of the air traffic around your area. Recently skies-adsb has been updated from version 1 to version 2, bringing with it several improvements.

The new improvements include:

  • Generate custom GeoJSON map layers from Natural Earth, FAA, and OpenStreetMap data
  • Aircraft trails visualization
  • Enhanced map renderer with multi-layer vector support:
    • Aerodromes
    • Airspaces
    • States / Provinces
    • Counties
    • Urban areas
    • Roads
    • Rivers
    • Lakes
  • New aircraft follow camera controls

The YouTube video below by the author demonstrates some of the new features.

skies-adsb v2 release - RTL-SDR ADS-B 3D plane tracking app