Digital Camera Becomes Video Transmitter

September 12, 2013 by Brian Benchoff 21 Comments

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In the arena of high altitude balloons, Canon’s PowerShot series of digicams are the camera du jour for sending high into the stratosphere. There’s a particular reason for this: these cameras can run the very capable CHDK firmware that turns a $100 digicam into a camera with a built-in intervalometer along with a whole bunch of really cool features. It appears this CHDK firmware is much more powerful than we imagined, because [Chris] is now transmitting pictures taken from a Canon a530 to the ground, using only the CHDK firmware and a cheap radio module.

These PowerShot cameras have an ARM processor inside that runs VxWorks, a minimal but very capable OS for embedded devices and Mars rovers. By tying in to the Tx and Rx lines of the camera, [Chris] can issue commands to the OS, change settings, and even install his own code.

With the help of [Phil Heron]’s SSDV encoder written in C, [Chris] was able to get the camera to transmit images with a small radio transmitter that fits in the battery compartment. Right now, [Chris] has only built the CHDK + SSDV for the Canon a530, but with how useful this build is, we expect to see an improved version very shortly.

An RTL-SDR Spectrum Analyzer

September 9, 2013 by Brian Benchoff 15 Comments

With the combination of small, powerful, and pocketable computers and cheap, off-the-shelf software defined radio receivers, it was only a matter of time before someone built a homebrew spectrum analyzer with these ingredients. This great build is the project of [Stephen Ong] and he’s even released all the softwares for you to build this on your own.

The two main components of this build are a BeagleBone Black and its 7″ Touchscreen cape. The BeagleBone is running Angstrom Linux, a blazingly fast Linux distro for small embedded devices. The radio hardware consists of only a USB TV tuner supported by RTL-SDR. In his demo video, [Stephen] shows off his project and by all accounts it is remarkable, with a UI better than most desktop-oriented SDR software suites.

You can grab the BeagleBone image [Stephen] is using over on his blog, but for more enterprising reader, he’s also put up the source of his ViewRF software up on GitHub.

A Comparison Of Hacker Friendly SDRs

August 23, 2013 by Eric Evenchick 61 Comments

In the market for a software defined radio? [Taylor Killian] wrote a comprehensive comparison of several models that are within the price range of amateurs and hobbyists.

You can get started with SDR using a $20 TV tuner card, but there’s a lot of limitations. These cards only work as receivers, are limited to a small chunk of the radio spectrum, and have limited bandwidth and sample rates. The new SDRs on the market, including the bladeRF, HackRF, and USRP offerings are purpose built for SDR experimentation. You might want an SDR to set up a cellular base station at Burning Man, scan Police and Fire radio channels, or to track ships.

[Taylor] breaks down the various specifications of each radio, and discusses the components used in each SDR in depth. In the end, the choice depends on what you want to do and how much you’re willing to spend. This breakdown should help you choose a hacker friendly SDR.

HackRF, Or Playing From 30 MHz To 6 GHz

August 1, 2013 by Brian Benchoff 49 Comments

Up on Kickstarter, [Michael Ossmann] is launching the HackRF, an inordinately cheap, exceedingly capable software defined radio tool that’s small enough to lose in your laptop bag.

The HackRF was the subject of a lot of interest last time it was on Hackaday – the ability to receive up to 6GHz allows the HackRF to do a lot of very interesting things, including listening in on Bluetooth, WiFi, and 4G networks. Also, the ability to transmit on these frequencies means a lot of very interesting, and quite possibly slightly evil applications are open to anyone with a HackRF. Like the RTL-SDR dongles, the HackRF works with GNU Radio out of the box, meaning all those cool SDR hacks we’ve seen so far will work with this new, more powerful board.

Compared to the USB TV tuner cards that were so popular a year ago, the HackRF has 10 times the bandwidth, is able to receive up to 6GHz, and is also able to transmit. It’s only half-duplex, so to receive and transmit simultaneously you’ll need two HackRFs, or maybe wait for a hardware revision that will hopefully come sooner rather than later.

Below you can check out [Michael]’s presentation at Toorcon where the HackRF was unleashed to the world.

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Retrotechtacular: A Tour Of WLW, A 500,000 Watt Radio Transmitter

July 26, 2013 by Mike Szczys 61 Comments

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This is an overview of a 500,000 Watt radio transmitter site. It’s one of the slides shared in a guided video tour of the transmitter’s hardware. The radio station — whose call sign was WLW — called itself the Nation’s Station because of its ability to reach so much of the country.

It operated at the 500 kW level starting back in the 1930’s. The technology at the time meant that there were a lot of challenges involved with transmitting at this level of power. It took 750 kW input to achieve the 500 kW output. To reach that the station had a set of AC motors in the basement generating the 4500 Amps at 33 Volts DC ~~needed to power the transmitter~~ to heat each filament. Obviously there was a lot of heat generated at the same time. The system was water-cooled. An elaborate network of Pyrex pipes carried distilled water to and from the tubes to handle the heat dissipation.

The video tour lasts about thirty minutes. It’s just packed with interesting tidbits from the experts leading the tour so add it to your watch list for some geeky entertainment over the weekend.

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[Travis Goodspeed] Starts A Space Agency In Southern Appalachia

July 23, 2013 by Mike Szczys 14 Comments

His space agency hardware might be in Southern Appalachia, but he can control it from anywhere in the world. That’s right, [Travis Goodspeed] started his own space agency — well kinda. The first piece of hardware operated by the organization is this dish for tracking moving targets in near space.

The main part of the build is a Felcom 82B dish which was designed to be a satellite link for naval vessels. The image showing the back side of it exposes all of the extras he built into the system. Don’t worry though, a dome goes over the top to keep the weather out without encumbering its operation.He uses an SDR dongle to handle the radio communications. That connects to a BeagleBone which pipes the data to his handheld over the Internet.

It’s amazing to see this type of hobby project. It wasn’t that long ago that you needed an entire room of hardware to communicate with satellites.

Long Distance PS3 Controller

June 19, 2013 by Brian Benchoff 15 Comments

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Sony’s DualShock 3 controller can be seen in a number of projects here on Hackaday. There’s a reason for this: it’s easy to sniff the Bluetooth signals coming out of this controller and make any electronics project do your remote control bidding. Bluetooth has a fairly limited range, though, so what happens if you’d like to use this very comfortable and very functional controller over a mile or so? Just replace the mainboard of the controller with a new design using an Xbee radio. It’s a great project from the workbench of [Marcel] and looks to be just the solution for an awesome Xbee remote control.

The Sony DualShock 3 controller is designed around a single main board for the bulk of the electronics and analog sticks with three daughterboards used for every other button on the controller. [Marcel] took the main board out of his controller and stated to reverse engineer the thing, keeping the USB charging, PC communication, force feedback and LED indicators. Instead of Bluetooth as in the original circuit, [Marcel] used a 60mW XBee radio, allowing him to control just anything connected to another XBee radio with a range of up to a mile.

[Marcel]’s new main board is a direct drop in replacement for the original DualShock 3 mainboard, and the only modification to the controller is drilling a small hole for the new antenna. It’s a great piece of kit for RC vehicles of any kind, and it’s fully programmable for whatever robotics project you might have in mind.

Thanks {Roel] for sending this one in.