Category: HackRF

Transmitting DATV DVB-S Video with the HackRF Blue

Simon (G0FCU) has been using his HackRF Blue to transmit DVB-S video captured from his video camcorder. In the ham radio hobby there is something called digital amateur television (DATV) in which amateurs transmit digital video over radio to repeaters. Simon writes that in the UK DATV is usually transmitted at above 1.2 GHz and in the DVB-S format, which is the same format used by some satellite TV services.

Although there are dedicated DATV radios, Simon decided that he wanted to use the HackRF Blue as the radio for transmitting his own DATV signals. To do this he uses the software dvgrab to grab the video stream from the camera, then passes it to ffmpeg to compress the raw video into MPEG-2 and then uses a GNU Radio program called gr-dvbs to use the HackRF to transmit the DVB-S stream at 1000 MHz.

To test that his signal was transmitting correctly, Simon then used a standard DVB-S satellite TV with the LNB bypassed. 

Previously we also posted about using a BladeRF for transmitting DATV DVB-T signals.

What the DVB-S output signal looks like on another HackRF.
What the DATV DVB-S output signal looks like on another HackRF.

New ExtIO for the HackRF and HDSDR

We’ve received a note from RTL-SDR.com reader Tim about a new ExtIO module available for the HackRF and HDSDR. ExtIO stands for External IO, and is a special DLL file that allows HDSDR and other software to access hardware like the HackRF.

To use it, simply copy the HackRF ExtIO dll file into the HDSDR directory, and select it when opening HDSDR. The module currently supports 2, 4, 8, 10, 12.5, 16 and 20 MSPS sample rates. We tested it briefly on our own HackRF and it ran just fine at all sample rates.

The module is available on GitHub and it’s current binary release can be downloaded here.

The HackRF running in HDSDR.
The HackRF running in HDSDR with the new ExtIO Module.

Installing and Testing the Optional RF Shield on the HackRF

Over on YouTube user Cameron Conover has uploaded a video where he tests the effectiveness of the optional HackRF RF shield and also shows how to install it. The shield solders on to the RF front end of the HackRF and is intended to block signals from entering the device other than through the antenna.

To test the effectiveness of the shield Cameron uses a signal generator to transmit a test signal at 406 MHz. He shows that without the shield in place the HackRF with a 50 Ohm terminator on the antenna input strongly picks up the test signal. After soldering in the shield and testing again, the test signal can no longer be picked up.

HackRF One optional RF shield Installation

HackRF Blue Shipped and HackRF One Updates

Back in December of last year we posted about the Indiegogo campaign for the HackRF Blue, a lower cost clone of the HackRF One software defined radio. They were able to achieve a lower cost by better component sourcing and manufacturing choices, thus reducing the cost from $299 to $200. The HackRF Blue Indiegogo campaign was successful and most of the HackRF Blue’s have now been shipped and delivered to backers. If you need help getting started with the HackRF Blue see http://hackrfblue.com/getting-started/. To get started on Windows, simply use Zadig like with the RTL-SDR, and use SDR# which has built in HackRF support.

The specs of the official HackRF One (and by extension the HackRF Blue) have also recently been changed. They now officially acknowledge that the HackRF One is capable of operating at a frequency down to about 1 MHz. They write:

Now that we’ve seen consistent low frequency performance across multiple manufacturing runs, we’re comfortable changing the official specification: HackRF One operates from 1 MHz to 6 GHz. Try attaching a long wire antenna to listen to shortwave radio!

Recently some people have been considering which mid priced SDR to upgrade to from their RTL-SDR. Our opinion is this: The HackRF has pretty poor RX performance, probably the same as, or even worse than the RTL-SDR, so we suggest you buy it only if you want TX capabilities or need operation above 1.7 – 2 GHz. If you only need RX then we suggest you choose the Airspy or SDRPlay as they have much better RX performance. See our list of SDRs for more possible options. 

The HackRF Blue.
The HackRF Blue.

Wireless Door Bell 433 MHz ASK Signal Analysis with a HackRF

Paul Rascagneres, an RF experimenter has recently uploaded a document detailing his efforts at reverse engineering a wireless doorbell (pdf file) with a 433 MHz Amplitude Shift Keyed (ASK) signal with his HackRF software defined radio. The HackRF is a SDR similar to the RTL-SDR, but with a wider available bandwidth and transmit capabilities.

To reverse engineer the doorbell, Paul used GNU Radio with the Complex to Mag decoder block to receive and demodulate the ASK signal. Once demodulated he was able to visually see the binary modulated waveform, and manually obtain the serial bit stream. From there he went on to create a GNU Radio program that can automatically obtain the binary strings from the ASK waveform.

In order to replay the signal, Paul found that the simplest way was to use the hackrf_transfer program, which simply records a signal, and then replays it via the HackRF transmitter on demand. With this method Paul was able to ring his doorbell via the HackRF.

Paul also confirmed his SDR results with an Arduino and 433 MHz transceiver. He then took it a step further and used the Arduino to create a system that could automatically receive and replay signals at 433 MHz and 315 MHz.

Decoding an ASK modulated bitstream.
Decoding an ASK modulated bitstream.

HackRF Controlling a Quadcopter

Over on YouTube user Mike has uploaded a video showing a quadcopter being controlled by the HackRF, a low cost transmit capable software defined radio. Mike uses a Hubson X4 quadcopter and controls it with a USB joystick coupled with GNU Radio. According to a tweet by Micheal Ossmann (the inventor of the HackRF), there were initially USB latency issues that caused problems, but have since been fixed by Mike.

HackRF quadcopter control

HackRF Blue: A Lower Cost HackRF

Earlier in the year the HackRF One was released by Micheal Ossmann. It is a transmit and receive capable software defined radio with a 10 MHz to 6 GHz range which currently sells for around $300 USD. Since the HackRF is open source hardware, anyone can make changes to the design and build and sell their own version.

The HackRF Blue is a HackRF clone that aims to sell at a lower cost. By sourcing lower cost parts that still work well in the HackRF circuit, the team behind the HackRF Blue were able to reduce the price of the HackRF down to $200 USD. They claim that the HackRF Blue has the same performance as the HackRF One and is fully compatible with the HackRF software. They are currently seeking funding through an IndieGoGo campaign.

Their main goal through the funding is to help provide underprivileged hackerspaces with a free HackRF.

The HackRF Blue
The HackRF Blue

Reverse Engineering a Wireless Alarm with the HackRF

Wireless alarms consist of multiples devices such as sensors and detectors which all communicate to a central control box via RF signals. Blogger “fun over ip” decided that he wanted to understand the design and security measures used by his Verisure wireless alarm by reverse engineering the system.

First, he took his HackRF software defined radio and monitored the 433 MHz and 868 MHz ISM bands whilst pushing keys on his alarms remote control. In the 868 MHz band he found a corresponding signal that had two spikes in the RF spectrum, indicating that it was likely a 2-FSK (frequency shift keyed) signal.

Next he created a GNU Radio program to demodulate the 2-FSK signal into a binary sequence. He then used Audacity to view and analyze the binary sequence, decoding it into 0’s and 1’s and determining the sync word (or access code). With further analysis he also determined the symbol rate and samples per symbol. With all this information gathered, he was then able to expand his GNU Radio program to automatically detect and decode packets sent by the various wireless devices connected to the alarm system.

His post goes into good detail about the steps that he took and is a great aide in understanding how to reverse engineer wireless protocols.

Decoding Wireless Alarms
Decoding Wireless Alarms