Listening to D-STAR digital voice with DSD 1.7

Brazilian amateur radio operator PU2VLW has written a post (in Portugese) detailing how to use DSD version 1.7 to decode amateur radio D-STAR digital voice transmissions. (Google translate may be helpful.) DSD can be downloaded as source from GitHub. His setup uses a Windows machine running SDR# to receive the D-STAR signal using an RTL-SDR […]

Improved digital voice P25 decoding with DSDPlus

We previously posted about the DSD digital decoding software and it’s usefulness with the RTL-SDR dongle and other signal sources. Now there’s a newly released version known as DSDPlus which promises to deliver improved decoding and clearer audio of unencrypted APCO Project 25 (P25) radio signals. This program is designed to be used with your […]

DSD block for GNU Radio

Luke Berndt from the HackRF-dev forums has posted his work to make the functionality of DSD available to GNU Radio users in the form of a GRC block. “I have been playing around a bit and found an easy way to receive and playback digital LMR. More and more of the radio systems are going […]

RTL-SDR dsd tutorial: monitoring P25 digital voice

The crew over at has posted a simple tutorial on using the RTL-SDR dongle and free SDR# and Digital Speech Decoder software (dsd) to monitor P25 digital radio voice comms. They describe, “Digital radio voice communications are becoming more commonly used in the radio spectrum. This is due to the various improvements offered over […]

Decoding P25 with SDR#, DSD, and RTLSDR

This is another illustration of the amazing utility of the RTL-SDR and SDR# software. Here proct0r links the output from SDR# to a program known as DSD. DSD is an open source command line program originally coded in C by anonymous for Linux for the purpose of decoding digital protocols via a PC soundcard.

110v temperature controlled soldering station build no. 2

Mike Doughty from PCB Smoke shared his DIY 110v temperature controlled soldering station in the project log forum: This project is build number 2 of a 110v temperature controlled soldering station. It is a follow-up post to the project that I was working on last October. Blog post with complete details here. This version has […]

Garage door signal hacking using RTL-SDR and TI Chronos watch

Students Ido Livneh and Gil Freidlin from Tel Aviv University have been experimenting with garage door opener signals using the TI Chronos watch and RTL-SDR dongle. Their technique involves using the SDR along with HDSDR software to acquire and record the signal, which is then analyzed using Python based tools and encoded for loading onto […]

Digital Speech Decoder 1.7.0-dev adds D-Star support

DSD is a popular software tool for decoding various unencrypted digital radio protocols about which we’ve previously posted. We noticed that there is now a release of DSD which purports to be capable of decoding the amateur radio digital protocol known as D-Star. This is in addition to P25, X2-TDMA, ProVoice and NXDN offered in […]

Update: HackRF based SmartNet radio monitor

We previously posted about the GNURadio based scanner for SmartNet II digital radio systems. Now Luke Berndt has updated his project info and has posted samples of the decoded system audio online. It has taken a lot of futzing, but I have my HackRF recording the Washington DC’s Fire Dept radio system and making it […]

Decoding D-STAR headers with the RTL-SDR

D-STAR or Digital Smart Technologies for Amateur Radio is a digital voice and data protocol used in amateur radio. Here’s a link which shows how the RTL-SDR can decode D-STAR text messages and headers (link is in Italian but Google translate can help, and the pictures show more than enough information). By using SDRSharp and […]

GNURadio based scanner for SmartNet II digital radio systems

Luke Berndt posted on the HackRF-dev forum: “I built a Scanner app so I could use my HackRF to listen to my local fire department. It should work for any Moto SmartNet trunking systems that uses P25 CAI for the voice channels. It is based off the gr-smartnet code and uses DSD to decode the […]

DIY adapter for flashing ATtiny84/85 with the Bus Pirate

@indigoid tweeted this picture of his DIY adapter for flashing ATtiny84/85 with the Bus Pirate: Very dodgy DIY adapter for flashing ATtiny84/85 via Bus Pirate. Shown w/ ATtiny85. No more jumpers! Get an assembled Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

RDS reception using RTL-SDR dongle

If you have a RTL-SDR dongle and Windows machine you might want to try out this simple project. It’s a proof of concept using an Ubuntu machine with GNU Radio Companion to obtain the RDS signal from the FM broadcast. Then the data is sent over TCP to a Windows 7 machine, running a .NET […]

Free Virtual Audio Cable alternative

RTL-SDR enthusiasts who use Windows are familiar with the need for a virtual audio device to connect the SDR output to decoder programs such as dsd. The hangup is that you need to purchase Virtual Audio Cable software to the tune of $25 (more than the cost of the SDR dongle itself.) Now there’s a […]

TIDeals: eZ430-Chronos watch again

If you missed it before, TI is offering the Chronos Watch as their current week’s deal at $38 (plus shipping.) The eZ430 deal includes the wireless enabled watch, CC1111 USB RF access point, and a CD containing software and documentation. This is the watch featured in a recent post on hacking RF devices in the […]

DP6037 SMT.v1 free PCB build

Cosminnci posted pictures of his free DP6037_SMT.v1 PCB build. This is a universal breakout board for SOIC microcontrollers. It features a USB power supply and data lines, a quartz crystal, breakouts for all the pins and a small prototyping area. This board was really fun to build, I wanted to get a PIC18F2550 breakout board, but […]