Hackaday Links: August 30, 2014

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Adafruit did another Circuit Playground, this time concerning frequency. If you’re reading this, no, it’s probably not for you, which is great because it’s not meant to be. If you have some kids, though, it’s great. Not-muppet robots and oscilloscopes. Just great.

The Hack42 space in Arnhem, Neterhlands recently got an offer: clean out a basement filled with old computer equipment, and it’s yours. Everything in the haul had to fit through an 80cm square door, and there are some very heavy, very rare pieces of equipment here. It’ll be a great (and massive) addition to their museum. There’s a few pics from the cleanout here and here.

[Mike] has been working on a project to convert gerber files into SVGs and it’s great.

[Carl] did a roundup of all the currently available software defined radios available. It’s more than just the RTL-SDR, HackRF, and BladeRF, and there’s also a list of modifications and ones targeted explicitly to the ham crowd.

This is a Facebook video, but it is pretty cool. It’s a DIY well pump made in Mexico. A few rubber disks made out of an old inner tube, a bit of PVC pipe, and a string is all you need to bring water to ground level.

What can you do with a cellphone equipped with a thermal imaging camera? Steal PIN codes, of course. Cue the rest of the blogosphere sensationalizing this to kingdom come. Oh, what’s that? Only Gizmodo took the bait?

About a year ago, we saw a pretty cool board made by [Derek] to listen in on the CAN bus in his Mazda 3. Now it’s a Kickstarter, and a pretty good one at that.

Your connectors will never be this cool. This is a teardown of a mind bogglingly expensive cable assembly, and this thing is amazing. Modular connectors, machined copper shields, machined plastic stress relief, and entire PCBs dedicated to two caps. Does anyone know what this mated to and what the list price was?

 

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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Hackaday Links: July 27, 2014

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Taking apart printers to salvage their motors and rods is a common occurrence in hacker circles, but how about salvaging the electronics? A lot of printers come with WiFi modules, and these can be repurposed as USB WiFi dongles. Tools required? And old printer, 3.3 V regulator, and a USB cable. Couldn’t be simpler.

The Raspberry Pi has a connector for a webcam, and it’s a very good solution if you need a programmable IP webcam with GPIOs. How about four cameras?. This Indiegogo is for a four-port camera connector for the Raspi. Someone has a use for this, we’re sure.

The one flexible funding campaign that isn’t a scam. [Kyle] maintains most of the software defined radio stack for Arch Linux, and he’s looking for some funds to improve his work. Yes, it’s basically a ‘fund my life’ crowdfunding campaign, but you’re funding someone to work full-time on open source software.

Calibration tools for Delta 3D printers. It’s just a few tools that speed up calibration, made for MATLAB and Octave.

[Oona] is doing her usual, ‘lets look at everything radio’ thing again, and has a plan to map microwave relay links. If you’ve ever seen a dish or other highly directional antenna on top of a cell phone tower, you’ve seen this sort of thing before. [Oona] is planning on mapping them by flying a quadcopter around, extracting the video and GPS data, and figuring out where all the other microwave links are.

PowerPoint presentations for the Raspberry Pi and BeagleBone Black. Yes, PowerPoint presentations are the tool of the devil and the leading cause of death for astronauts*, but someone should find this useful.


* Yes, PowerPoint presentations are the leading cause of death for astronauts. The root cause of the Columbia disaster was organizational factors that neglected engineer’s requests to use DOD space assets to inspect the wing, after which they could have been rescued. These are organizational factors were, at least in part, caused by PowerPoint.

Challenger was the same story, and although PowerPoint didn’t exist in 1986, “bulletized thinking” in engineering reports was cited as a major factor in the disaster. If “bulletized thinking” doesn’t perfectly describe PowerPoint, I don’t know what does.

As far as PowerPoint being the leading cause of death for astronauts, 14 died on two shuttles, while a total of 30 astronauts died either in training or in flight.

A GSM Base Station With Software Defined Radio

gsmIf you’re wondering how to get a better signal on your cellphone, or just want to set up your own private cell network, this one is for you. It’s a GSM base station made with a BeagleBone Black and a not too expensive software defined radio board.

The key component of this build is obviously the software defined radio. [Julian] is using a USRP B200 radio for this project. It’s not cheap, but it is a very nice piece of hardware capable of doing just about anything with GNU Radio. This board is controlled by a BeagleBone Black, a pretty cheap solution that puts the total cost of the hardware somewhere around $750.

The software side of the build is mostly handled by OpenBTS, the open source project for the software part of a cell station. This controls the transceiver, makes calls and SMS, and all the backend stuff every other cell station does. OpenBTS also includes support for Asterisk, the software of choice for PBX and VoIP setups. Running this allows you to make calls and send texts with your SDR-equipped, Internet-enabled BeagleBone Black anywhere on the planet.

THP Entry: SatNOGS

NOGS Here’s an interesting thought: it’s possible to build a cubesat for perhaps ten thousand dollars, and hitch a ride on a launch for free thanks to a NASA outreach program. Tracking that satellite along its entire orbit would require dozens of ground stations, all equipped with antennas, USB TV tuners, and a connection to the Internet. It’s actually more expensive to build and launch a cubesat than it costs to build a network of ground stations to get reasonably real-time telemetry from a cubesat. The future is awesome and weird, it seems.

This is the observation the guys behind SatNOGS have made. They’re developing a platform for a completely open source ground station network, with the idea being people an institutions along every longitude and latitude would build a simple satellite tracking antenna mount, connect it to the Internet, and become part of an open source Near Space Network, capable of receiving telemetry from any one of the small cubesats whizzing around in low earth orbit.

Despite being what is probably one of the most ambitious and far-reaching projects in open source hardware, the design of the system is relatively simple: the hardware is a 3D printed alt-az mount, capable of pointing a pair of antennas anywhere in the sky. The stepper motor driver board is based on the Arduino, and the computer running each antenna node is powered by a BeagleBone Black or a WR703N router. The antenna receiver is, of course, an RTL-SDR dongle, capable of listening to all the common cubesat bands. Even the software is derived from open source projects. Tracking a satellite across the sky can be calculated with GPredict, and the team is working on an observation scheduling and management system that combines multiple ground stations for coverage across the globe.

It’s a great idea, crowdsourcing satellite tracking from people around the globe, and something that could be used by hundreds of institutions lucky enough to launch a small cube of electronics into orbit.


SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

ISEE-3: On Track To Come Home

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Intended trajectory from ICE team in 1986 (blue), 2001 ephemeris of ISEE-3 (white) and current ephemeris (red/green). Click to embiggen.

When last we heard of the progress of commanding the derelict ISEE-3 satellite into stable orbit between the Earth and the sun, the team had just made contact with the probe using the giant dish in Arecibo, sent a few commands, and started gathering data to plot where the spacecraft is and where it will be. A lot has happened in a week, and the team is now happy to report the spacecraft is alive and well, and much, much closer to the intended trajectory than initially believed.

Before last week, the best data on where ISEE-3 was heading was from a 13-year-old data set, leaving the project coordinators to believe a maneuver of about 50-60  m/s was necessary to put the spacecraft into the correct orbit between the Earth and the sun. With new data from Arecibo, that figure has been reduced to about 5.8 m/s, putting it extremely close to where the original ICE navigation team intended it to go, all the way back in 1986. This also gives the team a bit of breathing room; the original planned maneuver to capture the spacecraft required nearly a third of the available fuel on board. The new plan only requires the spacecraft expend about 5% of its fuel stores. This, of course, brings up the idea of continuing the planned mission of the rebooted ISEE-3 beyond the Earth-Sun L1 point, but that is very much putting the cart before the horse.

Of course, getting ranging data of the spacecraft is only a small part of what has happened with the ISEE-3 part this week. Thanks to the ‘away team’ sent to Arecibo to install hardware and attempt to make contact with the satellite, both transceivers are working, telemetry is being downloaded from the probe, and work has begun on refining the exact position of ISEE-3 to compute where and when the spacecraft needs to make its maneuver.

Regular Hackaday feature and software defined radio god [Balint] was on hand with the away team at Arecibo to install his company’s SDR unit on the largest dish on the planet. His happy dance of the first data from ISEE-3 made the blog rounds, but the presentation (PDF) and photo gallery tell the story of working on the largest dish on the planet much better.

There’s still a lot of work to be done by the ISEE-3 team as they figure out how best to capture the spacecraft and prepare for the burn in the following week. They should have the exact orbit of ISEE-3 nailed down early this week, and after that, ISEE-3 could on a path back home in less than two weeks.

Building A Software Defined Radio With A Teensy

[Rich, VE3MKC] has been wanting to get into Software Defined Radio for a while now, but didn’t want to go the usual PC route. He initially thought the Raspberry Pi would be the best platform for a small, embedded device that could manipulate audio, but after discovering the ARM-powered Teensy 3.0, had an entirely different project in mind.

[Rich] is using a SoftRock SDR to take RF from an antenna and downconvert it into the audio range. Doing DSP for SDR is fairly computationally intensive, but he found a Teensy 3.0 with the audio adapter board was more than up to the task.

So far, [Rich] is running the audio from the SoftRock to the Teensy where the audio is digitized and multiplied with a VFO, sent through a filter and then sent to the output of the headphone jack to a speaker. The volume pot on the audio adapter board is used to tune the VFO, something [Rich] be replacing with a proper encoder sometime in the future.

In the videos below, you can see [Rich] listening in on a contest with a tiny TFT display showing everybody on the air. It’s a very cool build, and even though it’s still very early in development, there’s still a whole lot of CPU cycles for the Teensy to do some very cool stuff.

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