Category Archives: software-defined radio

Emergency Cell Tower on a Budget

Cell phone towers are something we miss when we’re out of range, but imagine how we’d miss them if they had been destroyed by disastrous weather. In such emergencies it is more important than ever to call loved ones, and tell them we’re safe. [Matthew May] and [Brendan Harlow] aimed to make their own secure and open-source cellular network antenna for those occasions. It currently supports calling between connected phones, text messaging, and if the base station has a hard-wired internet connection, users can get online.

This was a senior project for a security class, and it seems that the …read more

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Posted in cell, cell phone, Cellphone Hacks, cellular, gsm, phone, sdr, software-defined radio, telephone, tower | Leave a comment

ColibriNANO USB SDR Receiver Reviewed

At first glance, the ColibriNANO SDR looks like another cheap SDR dongle. But after watching [Mile Kokotov’s] review (see video below), you can see that it was built specifically for software defined radio service. When [Mile] takes the case off, you notice the heavy metal body which you don’t see on the typical cheap dongle. Of course, a low-end RTL-SDR is around $20. The ColibriNANO costs about $300–so you’d hope you get what you pay for.

The frequency range is nominally 10 kHz to 55 MHz, although if you use external filters and preamps you can get to 500 MHz. …read more

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Posted in radio hacks, sdr, software-defined radio | Leave a comment

The Breadboard RF103

When [ik1xpv] sets out to build a software-defined radio (SDR), he doesn’t fool around. His Breadboard RF103 sports USB 3.0, and 16-bit A/D converter that can sample up to 105 Msps, and can receive from 0 to 1800 MHz. Not bad. Thanks to the USB 3.0 port, all the signal processing occurs in the PC without the limitations of feeding data through a common sound port. You can see the device in action in the video below.

The Cypress FX3 USB device is an ARM processor, but it is only streaming data, not processing it. You can find the slightly …read more

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Posted in fx3, sdr, software-defined radio, usb 3.0, wireless hacks | Leave a comment

If The I And Q Of Software Defined Radio Are Your Nemesis, Read On

For those of us whose interests lie in radio, encountering our first software defined radio must have universally seemed like a miracle. Here is a surprisingly simple device, essentially a clever mixer and a set of analogue-to-digital or digital-to-analogue converters, that can import all the complex and tricky-to-set-up parts of a traditional radio to a computer, in which all signal procession can be done using software.

When your curiosity gets the better of you and you start to peer into the workings of a software defined radio though, you encounter something you won’t have seen before in a traditional radio. …read more

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Posted in Engineering, Hackaday Columns, I/Q, quadrature, quadrature mixer, radio hacks, sdr, software-defined radio | Leave a comment

SDR and Node.js Remote-Controlled Monster Drift

Most old-school remote controlled cars broadcast their controls on 27 MHz. Some software-defined radio (SDR) units will go that low. The rest, as we hardware folks like to say, is a simple matter of coding.

So kudos to [watson] for actually doing the coding. His monster drift project starts with the basics — sine and cosine waves of the right frequency — and combines them in just the right durations to spit out to an SDR, in this case a HackRF. Watch the smile on his face as he hits the enter key and the car pulls off an epic …read more

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Posted in HackRF, javascript, node.js, sdr, software-defined radio, wireless hacks | Leave a comment

Raspberry Pi SDR

[Chris D] noticed that the excellent software defined radio (SDR) software gqrx will run on the Raspberry Pi now. So he married a Raspberry Pi 3, a touchscreen, an RTL-SDR dongle, and an upconverter to make a very nice receiver setup. You can see the receiver in action below.

The video is a little light on build details, but there is a shot of the setup with the pieces labeled, and you should be able to figure it out from there. Of course, gqrx works with lots of different SDR devices so you might have to make adjustments depending on …read more

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Posted in GQRX, radio hacks, Raspberry Pi, sdr, software-defined radio | Leave a comment

Building A LoRa PHY With SDR

The Internet of Things is terrible when it’s your toaster. The real fun happens when you have hundreds or thousands of sensors sending data back to a base station every day. That requires low power, and that means LPWAN, the Low Power Wide Area Network.

There are a lot of options for LPWAN, but few are a perfect fit. LoRa is one of the rare exceptions, offering years of operation on a single AA cell, and range measured in miles. Layers two and three of LoRa are available as public documentation, but until now layer one has been patented and …read more

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Posted in LoRa, low power, LPWAN, sdr, software-defined radio, wireless hacks | Leave a comment