Shmoocon 2017: Software Defined Radio for Terahertz Frequencies

Before Bluetooth, before the Internet of Things, and before network-connected everything, infrared was king. In the 90s, personal organizers, keyboards, Furbys, and critical infrastructure was built on infrared. Some of these devices are still around, hiding in plain sight. This means there’s a lot of opportunities for some very fun exploits. This was the focus of [Mike Ossmann] and [Dominic Spill]’s talk at this year’s Shmoocon, Exploring The Infrared World. What’s the hook? Using software-defined radio with terahertz frequencies.

[Dominic]’s infrared detector
Infrared communication hasn’t improved since the days of IrDA ports on laptops, and this means the hardware required to talk to these devices is exceptionally simple. The only thing you need is an IR phototransistor and a 4.7k resistor. This is enough to read signals, but overkill is the name of the game here leading to the development of the Gladiolus GreatFET neighbor. This add-on board for the GreatFET is effectively a software defined IR transceiver capable of playing with IrDA, 20 to 60 kHz IR remote control systems, and other less wholesome applications.

Demos are a necessity, but the world seems to have passed over IR in the last decade. That doesn’t mean there still aren’t interesting targets. A week before Shmoocon, [Mike Ossmann] put out the call on Twitter for a traffic light and the associated hardware. Yes, police cars and ambulances use infrared signaling to turn traffic lights green. You shouldn’t. You can, but you shouldn’t.

What was the takeaway from this talk? IR still exists, apparently. Yes, you can use it to send documents directly from your PalmPilot to a laser printer without any wires whatsoever. One of the more interesting applications for IR is an in-car wireless headphone unit that sends something almost, but not quite, like pulse coded audio over infrared. The demo that drew the most applause was an infrared device that changed traffic lights to green. The information to do that is freely available on the web, but you seriously don’t want to attempt that in the wild.

Cordless Drill Uses no Electricity

There are few projects on how to make your own cordless drill, but what sets [Johnnyq90’s] amazing project apart is the fact that his power plant is a nitro engine. Not an easy task of course, but he makes it look easier than it is, and we really enjoyed the construction process.

He uses an RC Kyosho GX12 engine that was previously modified, changing the cooling head with a larger one. The engine drives a gearbox that was taken from another drill. All other parts were hand made. The clutch was carefully machined, and the cooling fan was made in a 3D printer. Other necessary parts were the frame, brass spacers to adjust the engine height and alignment, throttle arm and handle. In the end even the gearbox had to be modified for higher speed. The finished drill sure looks and sounds terrific, and seems to be perfectly capable of doing its job.

As with other mechanical projects from [Johnnyq90], the video has good timing and attention to detail. His channel is definitely worth a visit, specially if you like turbines.

Shmoocon 2017: Dig Out Your Old Brick Phone

The 90s were a wonderful time for portable communications devices. Cell phones had mass, real buttons, and thick batteries – everything you want in next year’s flagship phone. Unfortunately, Zach Morris’ phone hasn’t been able to find a tower for the last decade, but that doesn’t mean these phones are dead. This weekend at Shmoocon, [Brandon Creighton] brought these phones back to life. The Motorola DynaTAC lives again.

[Brandon] has a history of building ad-hoc cell phone networks. A few years ago, he was part of Ninja Tel, the group that set up their own cell phone network at DEF CON. That was a GSM network, and brickphones are so much cooler, so for the last few months he’s set his sights on building out a 1G network. All the code is up on GitHub, and the hardware requirements for building a 1G tower are pretty light; you can roll your own 1G network for about $400.

The first step in building a 1G network, properly referred to as an AMPS network, is simply reading the documentation. The entire spec is only 136 pages, it’s simple enough for a single person to wrap their head around, and the concept of a ‘call’ really doesn’t exist. AMPS looks more like a trunking system, and the voice channels are just FM. All of this info was translated into GNU Radio blocks, and [Brandon] could place a call to an old Motorola flip phone.

As far as hardware is concerned, AMPS is pretty lightweight when compared to the capabilities of modern SDR hardware. The live demo setup used an Ettus Research USRP N210, but this is overkill. These phones operate around 824-849 MHz with minimal bandwidth, so a base station could easily be assembled from a single HackRF and an RTL-SDR dongle.

Yes, the phones are old, but there is one great bonus concerning AMPS. Nobody is really using these frequencies anymore in the US. That’s not to say building your own unlicensed 1G tower in the US is legally permissible, but if nobody reports you, you can probably get away with it.

Review: Hammer-Installed Solderless Raspberry Pi Pin Headers

A few days ago we reported on a new product for owners of the Raspberry Pi Zero, a set of solderless header pins that had a novel installation method involving a hammer. We were skeptical that they would provide a good contact, and preferred to stick with the tried-and-trusted soldered pins. It seems a lot of you agreed, and the comments section of the post became a little boisterous. Pimoroni, the originator of the product, came in for a lot of flak, with which to give them their due they engaged with good humor.

It’s obvious this was a controversial product, and maybe the Hackaday verdict had been a little summary based on the hammer aspect of the story. So to get further into what all the fuss had been about I ordered a Pi Zero and the solderless pin kit to try for ourselves.

Continue reading “Review: Hammer-Installed Solderless Raspberry Pi Pin Headers”

The ARRL Raises A Stink About Illegal FPV Transmitters

We have all been beneficiaries of the boom in availability of cheap imported electronics over the last decade. It is difficult to convey to someone under a certain age the step change in availability of parts and modules that has come about as a result of both the growth of Chinese manufacturing and Internet sales that allow us direct access to sellers we would once only have found through a lengthy flight and an intractable language barrier.

So being able to buy an ESP8266 module or an OLED display for relative pennies is good news, but there is a downside to this free-for-all. Not all the products on offer are manufactured to legal standards wherever in the world we as customers might be, and not all of them are safe to use. We’ve all seen teardowns of lethal iPhone charger knock-offs, but this week the ARRL has highlighted an illegal import that could take being dangerous to a whole new level as well as bring an already beleaguered section of our community to a new low.

The products the radio amateurs are concerned about are video transmitters that work in the 1.2GHz band. These are sold for use with FPV cameras on multirotors, popularly referred to as drones, and are also being described as amateur radio products though their amateur radio application is minimal. The ARRL go into detail in their official complaint (PDF) about how these devices’ channels sit squarely over the frequencies used by GLONASS positioning systems, and most seriously, the frequencies used by the aircraft transponders on which the safety of our air traffic control system relies.

The multirotor community is the unfortunate recipient of a lot of bad press, most of which is arguably undeserved and the result of ignorant mass media reporting. We’ve written on this subject in the past, and reported on some of the proposals from governments which do not sound good for the enthusiast. It is thus a huge concern that products like those the ARRL is highlighting could result in interference with air traffic, this is exactly not the association that multirotor fliers need in a hostile environment.

The ARRL complaint highlights a particular model with a 5W output, which is easily high enough to cause significant interference. It is however just one of many similar products, which a very straightforward search on the likes of AliExpress or eBay will find on sale for prices well under $100. So if you are concerned with multirotors we’d urge you to ensure that the FPV transmitters you or your friends use are within the legal frequencies and power levels. We’re sure none of you would want an incident involving a manned aircraft on your conscience, nor would you relish the prospect of the encounter with law enforcement that would inevitably follow.

In the past we’ve taken a look at some of the fuss surrounding reported drone incidents, and brought you news of an Australian sausage lover in hot water for drone-based filming. It’s a hostile world out there, fly safe!

Autonomous Delivery: Your Impulse Buys Will Still Be Safe

I heard a “Year in Review” program the other day on NPR with a BBC World Service panel discussion of what’s ahead for 2017. One prediction was that UAV delivery of packages would be commonplace this year, and as proof the commentator reported that Amazon had already had a successful test in the UK. But he expressed skepticism that it would ever be possible in the USA, where he said that “the first drone that goes over somebody’s property will be shot down and the goods will be taken.”

He seemed quite sincere about his comment, but we’ll give him the benefit of the doubt that he was only joking to make a point, not actually grotesquely ignorant about the limitations of firearms or being snarky about gun owners in the US. Either way, he brings up a good point: when autonomous parcel delivery is commonplace, who will make sure goods get to the intended recipient?

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Raspberry Pi Launches Compute Module 3

The forgotten child of the Raspberry Pi family finally has an update. The Raspberry Pi Compute Module 3 has been launched.

The Pi 3 Compute Module was teased all the way back in July, and what we knew then is just about what we know now. The new Compute Module is based on the BCM2837 processor – the same as found in the Raspberry Pi 3 – running at 1.2 GHz with 1 gigabyte of RAM. The basic form factor SODIMM form factor remains the same between the old and new Compute Modules, although the new version is 1 mm taller.

The Compute Module 3 comes with four gigabytes of eMMC Flash and sells for $30 on element14 and RS Components. There’s also a cost-reduced version called the Compute Module 3 Light that forgoes the eMMC Flash and instead breaks out those pins to the connector, allowing platform integrators to put an SD card or Flash chip on a daughter (mother?) board. The CM3 Lite version sells for $25. Continue reading “Raspberry Pi Launches Compute Module 3”