DEFCON 22: The HackRF PortaPack

What do you get when you combine one of the best (and certainly one of the best for the price) software defined radios with the user interface of a 10-year-old iPod? The HackRF PortaPack, developed by [Jared Boone], and demonstrated at DEFCON last weekend.

[Jared] is one of the original developers for the HackRF, a 10MHz to 6GHz software defined radio that can also transmit in half duplex. Since the development of the HackRF has (somewhat) wrapped up, [Jared] has been working on the PortaPack, an add-on for the HackRF that turns it into a portable, ARM Cortex M4-powered software defined radio. No, it’s not as powerful as a full computer running GNU Radio, but it does have the capability to listen in on a surprising amount of radio signals.

Because [Jared] is using a fairly low-power micro for the PortaPack, there’s a lot of tricks he’s using to get everything running smoothly. He gave a lightning talk at the Wireless Village at DEFCON going over the strengths and weaknesses of the chip he’s using, and surprisingly he’s using very little floating point arithmetic in his code. You can check out the video for that talk below.

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THP Entry: A 433MHz Packet Cloner

ookloneThe first generation of The Internet Of Things™ and Home Automation devices are out in the wild, and if there’s one question we can ask it’s, “why hasn’t anyone built a simple cracking device for them”. Never fear, because [texane] has your back with his cheap 433MHz OOK frame cloner.

A surprising number of the IoT and Home Automation devices on the market today use 433MHz radios, and for simplicity’s sake, most of them use OOK encoding. [Texane]‘s entry for THP is a simple device with two buttons: one to record OOK frames, and a second to play them back.

Yes, this project can be replicated with fancy software defined radios, but [Texane]‘s OOKlone costs an order of magnitude less than the (actually very awesome) HackRF SDR. He says he can build it for less than $20, and with further refinements to the project it could serve as a record and play swiss army knife for anything around 433MHz. Video demo of the device in action below.

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Poor Audio Quality Made Great: Listen to Vintage Music Using an Antique Radio Without Removing the Insides

Sometimes it is not how good but how bad your equipment reproduces sound. In a previous hackaday post the circuitry of a vintage transistor radio was removed so that a blue tooth audio source could be installed and wired to the speaker. By contrast, this post will show how to use the existing circuitry of a vintage radio for playing your own audio sources while at the same time preserving the radio’s functionality. You will be able to play your music through the radio’s own audio signal chain then toggle back to AM mode and listen to the ball game. Make a statement – adapt and use vintage electronics.

Pre-1950’s recordings sound noisy when played on a high-fidelity system, but not when played through a Pre-War console radio. An old Bing Crosby tune sounds like he is broadcasting directly into your living room with a booming AM voice. You do not hear the higher frequency ‘pops’ and ‘hiss’ that would be reproduced by high-fidelity equipment when playing a vintage recording. This is likely due to the fact that the audio frequency signal chain and speaker of an antique radio are not capable of reproducing higher frequencies. Similarly, Sam Cooke sounds great playing out of an earlier transistor radio. These recordings were meant to be played on radios from the era in which they were recorded.

Choosing an Antique Radio

Vintage radios can be found at garage sales, estate sales, hamfests, antique shops, antique radio swap meets, and Ebay. Millions of radios have been manufactured. People often give them away. For this reason, antique radios are relatively inexpensive and the vast majority are not rare or valuable.

Generally speaking, tube radios must be serviced and may not even work. Transistor radios often work to some level. Try to find a radio that is clean and uses a power supply transformer or batteries.

Click past the break to learn how to restore these radios to working condition

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Dots and Dashes… on a Roll!

morse code device

Morse code was once a staple of the communications industry, but with advancing technology it has become relegated almost exclusively to movies and a niche group of ham radio operators. [Jan] has created a device which might not put a stop to this trend, but will at least educate children on the basics of how Morse code works by visually displaying Morse code as it’s generated.

The setup is fairly simple. An old momentary switch (which could easily be used in an actual Morse code setup) activates two pieces of circuitry. The first is a 555 timer circuit that creates an audible tone when the switch is pressed so the user can hear exactly what an operator would hear when decoding a real Morse code message.

The second piece of circuitry is where the real genius lies: a continuously spinning roll of glow-in-the-dark tape is placed in front of a white LED. When the switch is pressed, the LED turns on, which produces dots and dashes on the roll of tape as it passes by. This eliminates the need for rolls of paper or a more complicated moving pen/pencil setup to draw on the paper which might also be less child-proof.

While [Jan] built this as a toy, the children who used it thoroughly enjoyed it! They even decoded some Morse code messages and used the device to practice on it. After a while they’ll easily be able to master the Morse code trainer!

A Dead Simple, Well Constructed FM Transmitter

tx

[Angelo] is only 15, but that doesn’t mean his fabrication skills are limited to Lego and K’Nex. He’s built himself an amazingly well constructed FM transmitter that’s powerful enough to be received a quarter mile away.

The FM transmitter circuit itself is based off one of [Art Swan]‘s builds, but instead of the solderless breadboard construction you would expect to find in a small demo circuit, [Angelo] went all the way, etching his own PCB and winding his own coil.

Using photosensitized copper clad board, [Angelo] laid out the circuit with Fritzing, etched a board, and went at it with a drill. The components found in the transmitter are pretty standard and with the exception of the trimmer cap and electret mic, can be picked up in the parts drawers of any Radio Shack. He gets bonus points for using a 1/4 – 20 bolt for winding the coil, too.

The power supply for the transmitter is a single 9V battery, the battery connector being salvaged from a dead 9V. Awesome work, and for someone so young, [Angelo] already seems to have a grasp of all the random, seemingly useless information that makes prototyping so much easier. Video below.

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Fishing for Radio Signals With the Moxon Antenna

mox-antenna

[Bill Meara] has finished his latest project, a Moxon antenna for HF on 17 meters. [Bill] is well-known here on Hackaday. When not building awesome radios, he can be found ranting about ham radio. His new antenna turned out to be a true hack. He even used a hacksaw to build it!

The Moxon antenna is named for the late [Les Moxon, G6XN] who first described it in “Two-Element Driven Arrays”, a QST magazine article published in July of 1952.  [Bill] built his Moxon loosely based on [Jim/AE6AC's] excellent instructions. The design is incredibly simple – a two element directional antenna using crappie fishing poles as spreaders. That’s crappie as in the fish, not the quality of the pole. Crappie poles are typically made up of telescoping sections of graphite or fiberglass  in common lengths of 14, 16, and 20 feet. The poles can be bought for under $20 at sporting goods stores. [Bill] used 16 foot poles purchased from Amazon.

The antenna is created by connecting all four poles at their bases in an X shape. The wire elements are stretched across the ends of the poles. The entire antenna bends up as the stiff poles hold the driven and reflector elements in tension. [Bill] used some scrap wood and U-bolts to attach the fishing poles, and bungee cord ends at the tips. Since the antenna is directional, [Bill] added a TV antenna rotor to spin the beam around. The antenna is so light that one could get by with a couple of cords and the “Armstrong method” of antenna rotation.

Once up on the roof, [Bill] found his antenna really performed. He was easily able to cross the Atlantic from his Northern Virginia home to France, Belgium, and Latvia. The mostly horizontal antenna makes it a bit more unobtrusive than other directional designs. [Bill] mentions that his neighbors haven’t revolted yet, so he’s continuing to enjoy the fruits of his antenna labors.

HOPE X: Creating Smart Spaces With ReelyActive

When we hear about the Internet of Things, we’re thinking it’s a portable device with a sensor of some kind, a radio module, and the ability to push data up to the Internet. There’s nothing that says a device that puts data on the Internet has to be portable, though, as [Jeff] from ReelyActive showed us at HOPE X last weekend.

[Jeff]‘s startup is working on a device that turns every space into a smart space. It does this with radio modules connected to a computer that listen to Bluetooth and the 868, 915 and 2400MHz bands. These modules turn every place into a smart space, identifying who just walked into a room, and who is at a specific location. Think of it as the invisible foundation for any truly smart house.

The radio modules themselves are daisychained with Cat5 cable, able to be plugged into a hub or existing Ethernet drops. The software that makes the whole thing work can run on just about anything; if you want a Raspi to turn on the lights when you enter a room, or turn off a thermostat when you leave a building, that’s just a few lines of code and a relay.

The software is open source, and [Jeff] and his team are looking at making the hardware open. It’s a great idea, and something that would be a good entry for The Hackaday Prize, but ReelyActive is located in Montréal, and like Syria and North Korea, we’re not allowed to run a contest in Quebec.

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