An SDR For The Rest Of Them

If you are a radio enthusiast it is very likely that you will own at least one software defined radio. With the entry point into the world of SDRs starting with the ultra-cheap RTL2382 based USB receiver sticks originally designed for digital TV, it’s a technology that passed long ago into the impulse purchase bracket.

If you are not a radio enthusiast, or not even a Hackaday reader, you may not have heard of SDR technology. Even the humblest up-to-date radio or TV may well contain it somewhere within its silicon, but at the user interface it will still resemble the device you would have had in the 1950s: analogue tuning, or a channel-flipper.

It is interesting to see an attempt to market a consumer device that is unashamedly an SDR, indeed that is its unique selling point. The Titus II SDR bills itself as the “World’s First Consumer Ready SDR Package”, and is based around an Android tablet mated with a 100 kHz to 2 GHz SDR tuner and a pair of speakers in a portable radio styled case. It will support all modes including digital broadcasting through software plugins, and there will be an open plugin API for developers. They are taking pre-orders, and claim that the launch price will be under $100.

It sounds like an exciting product, after all who wouldn’t want a radio with those capabilities at that price! However it leaves us wondering whether the price point is just a little too ambitious for the hardware in question, and we’ll reluctantly say we’ll believe it when we see real devices on the market. A $100 consumer price doesn’t get you much in the tablet world, and that is from high-volume Chinese manufacturing without the extra cost of the SDR hardware and the overhead of smaller volume from a niche product. There are pictures online of real prototypes at trade shows, but we’d like to see a website with fewer renders and more hard plastic.

There is another angle to this device that might interest Hackaday readers though. It should remind anyone that building one yourself is hardly a difficult task. Take an RTL2382 stick with or without the HF modification, plug it into a tablet with an OTG cable, install an app like SDR Touch, and away you go. 3D print your own case and speaker surrounds as you see fit, and post the result on hackaday.io.

Via the SWLing Post.

Waiting For A Letter? This IoT Mailbox Will Tell You Exactly When It Arrives.

If you’re waiting for a much sought-after letter, checking your mailbox every five minutes can be a roller-coaster of emotion — not to mention time-consuming. If you fall into this trap, Hackaday.io user [CuriosityGym] as whipped up a mailbox that will send off an email once the snail-mail arrives.

The project uses an Arduino Uno, an ESP 8266 wifi module, and an idIoTware shield board — making specific use of its RGB LED and light dependent resistor(LDR). Configuring the RGB LED on the idIoTware board to a steady white light sets the baseline for the LDR, and when a letter is dropped in the box, the change in brightness is registered by the LDR, triggering the Arduino to send off the email.

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2,000 LEDs on Fire

What’s 18 feet tall, 12 feet wide, has 2,000 LEDs and turbine-driven blast furnaces? Believe it or not, it is a piece of kinetic sculpture created by [Therm] (a collective, not a person) for Burning Man 2016. The project is about 60% salvage, has a Raspberry Pi 3 helping its three human operators, and took a team of 30 about 9 months to complete.

The Raspberry Pi drives LED using fadecandy. You can see a video of the sculpture (three giant moths, to be exact) and a video about fadecandy, below. (We’ve covered a subtler fadecandy project before if you want to see a different take on it.)

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Put an Honest Face On Alexa With This HAL 9000 Build

Amazon put out a version of Alexa’s software that  could run on Raspberry Pi. Adafruit sold a big scary red button. For, [Keith Elliott] the project ahead was an obvious conclusion.

The Raspberry Pi version of Alexa’s software was lagging behind the release version. You had to press a button to input a command, which really steals a lot of the joy out of a creepy voice controlled robot listening to you putz around the house. Now, it can wake on command.

Since this sold him on finally adding Amazon’s ever watching witch eye to his home, he decided he would give it appropriately sinister clothes. These were 3D printed from files based on Adafruit’s guide. He ended up with a fairly convincing facade.

The inside is kind of melancholy. A lone Raspberry Pi 3 is held company by a microphone and audio amplifier. These are pretty much all that’s needed to make you home automated shopping experience dreams come true. Video after the break.

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Medium Over Message: A CD-ROM Multimedia Bubble Survivor’s Tale

Sometimes in the never-ending progression of technology, people take wrong turns. They pursue dead-ends they believe represent a bright future, often in spite of obvious indications to the contrary. IBM doggedly insisting Micro Channel Architecture was the future of PC hardware, for example, or Nokia’s seeming inability to recognise that the mobile phone experience had changed for ever when the first iPhones and Android devices appeared.

Every once in a while, that collective delusion grips an entire industry. All the players in a particular market nail their colours to a technology, seemingly without heed to what seems with hindsight to have been a completely obvious threat from the alternative that sidelined them. It is a tale of personal experience that prompts this line of thought, for the industry that tempted me away from hardware to a career in electronic publishing in the early 1990s was CD-ROM multimedia.

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A Linux Exploit That Uses 6502 Code

With ubiquitous desktop computing now several decades old, anyone creating an operating system distribution now faces a backwards compatibility problem. Each upgrade brings its own set of new features, but it must maintain compatibility with the features of the previous versions or risk alienating users. If you are a critic of Microsoft products for their bloat, this is one of the factors behind that particular issue.

As well as a problem of compatibility, this extra software overhead creates one of security. A piece of code descended from a DOS word processor of the 1980s for example was not originally created with any idea that it might one day be hiding in a library on a machine visible to the entire world by the Internet. Our subject today is a good example, just such a vulnerability hiding in an old piece of code whose purpose is to maintain an obscure piece of backward compatibility. [Chris Evans] has demonstrated a vulnerability in an Ubuntu version by playing an NES music file that contains exploit code emulated by the player on a virtual 6502 processor.

The NES Sound Format is a music file standard that packages Nintendo game music for playback. It contains a scripting language, and it is this that is used to trigger the vulnerability. When you open an NSF file on the affected Ubuntu system it finds its way via your music player and the gstreamer multimedia framework to libgstnsf.so, a gstreamer plugin for playing NSF files.

Rather unbelievably, his plugin works by emulating a real 6502 as found in a NES to derive the musical output, and it is somewhere here that the vulnerability exists. So not only do we have layer upon layer of backward compatibility to play an obscure music file format, there is also a software emulation of some 8-bit silicon from the 1970s. [Chris] comments “Is that cool or what?“, and while we agree that a 6502 emulator buried in a modern distro is cool, we can’t help thinking something’s been lost along the way.

A proof-of-concept is provided for Ubuntu 12.04. It’s an older version, but he points out that while he thinks the most recent releases should not contain exactly the same vulnerability, it certainly exists in more than one still-supported version. There’s also a worrying twist in that due to the vagaries of Ubuntu’s file manager it auto-opens when its folder is accessed from the GUI. The year 2000 called, they want their auto-opening Windows ME worms back.

Sadly we suspect the 6502 lurking in this music player can’t be put to more general-purpose use. If you manage it, please do share it with us! But if emulated 6502s are your thing, take a look at this 150MHz 6502 co-processor for an Acorn BBC Micro that someone made using a Raspberry Pi.

[via r/hacking]

6502 image, Dirk Oppelt, (CC BY-SA 3.0) via Wikimedia Commons.

The Little Mechanism That Made Precise Time-keeping Possible

There are few things to which we pay as much attention as the passage of time. We don’t want to be late for work, or a date. Even more importantly, we don’t want to age and die. Good time keeping is an all important human activity, and we started to worry about it as soon as we abandoned our hunter-gatherer lifestyle and agriculture and commerce emerged.

By de:Benutzer:Flyout - own work, http://de.wikipedia.org/wiki/Bild:Kerzenuhr.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1783765
A candle clock

Measuring time needs two things: a repetitive process to mark equal increments of time, and a way of tracking and displaying the result. The first timekeeping devices relied of course on the movement of the sun. Ancient Egyptians, around 3500 BC, built obelisks that, by casting a shadow on the ground at different positions, gave an approximate idea of the time. Next came the use of some medium that was consumed at a regular pace: candle, incense, water and sand clocks are examples. A great advancement came with the advent of the mechanical clock, and here is where the escapement mechanism appears.

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