Don’t Miss Watching this Solar Eclipse High Altitude Balloon Online

[Dan Julio] let us know about an exciting project that he and his team are working on at the Solid State Depot Makerspace in Boulder: the Solar Eclipse High Altitude Balloon. Weighing in at 1 kg and bristling with a variety of cameras, the balloon aims to catch whatever images are able to be had during the solar eclipse. The balloon’s position should be trackable on the web during its flight, and some downloaded images should be available as well. Links for all of that are available from the project’s page.

High altitude balloons are getting more common as a platform for gathering data and doing experiments; an embedded data recorder for balloons was even an entry for the 2016 Hackaday Prize.

If all goes well and the balloon is able to be recovered, better images and video will follow. If not, then at least a post-mortem of what the team thinks went wrong will be posted. Launch time in Wyoming is approximately 10:40 am Mountain Time (UTC -07:00) Mountain Daylight Time (UTC -06:00) on Aug 21 2017, so set your alarm!

Autonomous Boat Sails the High Seas

As the human population continues to rise and the amount of industry increases, almost no part of the globe feels the burdens of this activity more than the oceans. Whether it’s temperature change, oxygen or carbon dioxide content, or other characteristics, the study of the oceans will continue to be an ongoing scientific endeavor. The one main issue, though, is just how big the oceans really are. To study them in-depth will require robots, and for that reason [Mike] has created an autonomous boat.

This boat is designed to be 3D printed in sections, making it easily achievable for anyone with access to a normal-sized printer. The boat uses the uses the APM autopilot system and Rover firmware making it completely autonomous. Waypoints can be programmed in, and the boat will putter along to its next destination and perform whatever tasks it has been instructed. The computer is based on an ESP module, and the vessel has a generously sized payload bay.

While the size of the boat probably limits its ability to cross the Pacific anytime soon, it’s a good platform for other bodies of water and potentially a building block for larger ocean-worthy ships that might have an amateur community behind them in the future. In fact, non-powered vessels that sail the high seas are already a reality.

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Michael Ossmann Pulls DSSS Out of Nowhere

[Michael Ossmann] spoke on Friday to a packed house in the wireless hacking village at DEF CON 25. There’s still a day and a half of talks remaining but it will be hard for anything to unseat his Reverse Engineering Direct Sequence Spread Spectrum (DSSS) talk as my favorite of the con.

DSSS is a technique used to transmit reliable data where low signal strength and high noise are likely. It’s used in GPS communications where the signal received from a satellite is often far too small for you to detect visually on a waterfall display. Yet we know that data is being received and decoded by every cell phone on the planet. It is also used for WiFi management packets, ZigBee, and found in proprietary systems especially any dealing with satellite communications.

[Michael] really pulled a rabbit out of a hat with his demos which detected the DSSS signal parameters in what appeared to be nothing but noise. You can see below the signal with and without noise; the latter is completely indiscernible as a signal at all to the eye, but can be detected using his techniques.

Detecting DSSS with Simple Math

[Michael] mentioned simple math tricks, and he wasn’t kidding. It’s easy to assume that someone as experienced in RF as he would have a different definition of ‘simple’ than we would. But truly, he’s using multiplication and subtraction to do an awful lot.

DSSS transmits binary values as a set called a chip. The chip for digital 1 might be 11100010010 with the digital 0 being the inverse of that. You can see this in the slide at the top of this article. Normal DSSS decoding compares the signal to expected values, using a correlation algorithm that multiplies the two and gives a score. If the score is high enough, 11 in this example, then a bit has been detected.

To reverse engineer this it is necessary to center on the correct frequency and then detect the chip encoding. GNU radio is the tool of choice for processing a DSSS capture from a SPOT Connect module designed to push simple messages to a satellite communication network. The first math trick is to multiply the signal by itself and then look at spectrum analysis to see if there is a noticeable spike indicating the center of the frequency. This can then be adjusted with an offset and smaller spikes on either side will be observed.

When visualized in a constellation view you begin to observe a center and two opposite clusters. The next math trick is to square the signal (multiply it by itself) and it will join those opposite clusters onto one side. What this accomplishes is a strong periodic component (the cycle from the center to the cluster and back again) which reveals the chip rate.

Detecting symbols within the chip is another math trick. Subtract each successive value in the signal from the last and you will mostly end up with zero (high signal minus high signal is zero, etc). But every time the signal spikes you’re looking at a transition point and the visualization begins to look like logic traced out on an oscilloscope. This technique can deal with small amounts of noise but becomes more robust with a bit of filtering.

This sort of exploration of the signal is both fun and interesting. But if you want to actually get some work done you need a tool. [Michael] built his own in the form of a python script that cobbles up a .cfile and spits out the frequency offset, chip rate, chip sequence length, and decoded chip sequence.

Running his sample file through with increasing levels of noise added, the script was rock solid on detecting the parameters of the signal. Interestingly, it is even measuring the 3 parts per million difference between the transmitter and receiver clocks in the detected chip rate value. What isn’t rock solid is the actual bit information, which begins to degrade as the noise is increased. But just establishing the parameters of the protocol being used is the biggest part of the battle and this is a dependable solution for doing that quickly and automatically.

You can give the script a try. It is part of [Michael’s] Clock Recovery repo. This talk was recorded and you should add it to your reminder list for after the con when talks begin to be published. To hold you over until then, we suggest you take a look at his RF Design workshop from the 2015 Hackaday Superconference.

GPS Tracker Gets SMS Upgrade

In May of 2000, then-President Bill Clinton signed a directive that would improve the accuracy of GPS for anyone. Before this switch was flipped, this ability was only available to the military. What followed was an onslaught of GPS devices most noticeable in everyday navigation systems. The large amount of new devices on the market also drove the price down to the point where almost anyone can build their own GPS tracking device from scratch.

The GPS tracker that [Vadim] created makes use not just of GPS, but of the GSM network as well. He uses a Neoway M590 GSM module for access to the cellular network and a NEO-6 GPS module. The cell network is used to send SMS messages that detail the location of the unit itself. Everything is controlled with an ATmega328P, and a lithium-ion battery and some capacitors round out the fully integrated build.

[Vadim] goes into great detail about how all of the modules operate, and has step-by-step instructions on their use that go beyond what one would typically find in a mundane datasheet. The pairing of the GSM and GPS modules seems to go match up well together, much like we have seen GPS and APRS pair for a similar purpose: tracking weather balloons.

iPad, not Flux Capacitor, Brings DeLorean Back to the Future

Add a flux capacitor and a Mr. Fusion to a DeLorean and it becomes a time machine. But without those, a DeLorean is just a car. A 35-year old car at that, and thus lacking even the most basic modern amenities. No GPS, no Bluetooth — not even remote locks for the gullwing doors!

To fix that, [TheKingofDub] decided to deck his DeLorean out with an iPad dash computer that upgrades the cockpit experience, and we have to say we’re impressed by the results. Luckily, the space occupied by the original stereo and dash vents in the center console is the perfect size for an iPad mini, even with the Lightning cable and audio extension cable attached. A Bluetooth relay module is used to interface to the doors, windows, trunk, garage door remote, and outdoor temperature sensor. A WiFi backup camera frames the rear license plate. Custom software ties everything together with OEM-looking icons and a big GPS speedometer. The build looks great, adds functionality, and should make road trips a little easier.

When [TheKingofDub] finally gets sick of people complaining about where the BTTF guts are, maybe he can add a flux capacitor and time circuits.

[via r/electronics]

Hackaday Prize Entry: Yet Another Unmanned Vehicle Controller

To build any sort of autonomous vehicle, you need a controller. This has to handle all sorts of jobs – reading sensor outputs, controlling motors and actuators, managing power sources – controlling a vehicle of even moderate complexity requires significant resources. Modern cars are a great example of this – even non-autonomous vehicles can have separate computers to control the engine, interior electronics, and safety systems. In this vein, [E.N. Hering] is developing a modular autonomous vehicle controller, known as YAUVC.

The acronym stands for Yet Another Unmanned Vehicle Controller, though its former name – Fly Hard With A Vengeance – was not without its charms. The project is built around the concept of modularity and redundancy. The controller, designed primarily for flying vehicles, has an ATMega328P as its primary processor, into which various modules can be plugged in to handle different tasks.

This design choice has several benefits – having separate processors to handle individual jobs can make sense in real-time systems. You’d hardly want your quadcopter to crash because the battery management routines were stealing CPU time from the flight dynamics calculations. Instead, by offloading tasks to individual modules, each can run without interfering with the others. Modularity does come with drawbacks however — the problem of maintaining efficient communication between modules is one of them. [Hering] also plans to make sure the system can be set up to use multiples of the same module for redundancy – similar to modern flight systems in passenger aircraft that weigh the results of several computers to make decisions.

Much work has already been done – with the YAUVC platform already fleshed out with a backbone design as well as modules for WiFi, accelerometers and GPS navigation. We look forward to seeing YAUVC reaching flight-ready status soon!

Hackaday Prize Entry: USB GSM GPS 9DOF SD TinyTracker Has All the Acronyms

[Paul] has put together an insanely small yet powerful tracker for monitoring all the things. The USB TinyTracker is a device that packages a 48MHz processor, 2G modem, GPS receiver, 9DOF motion sensor, barometer, microphone, and micro-SD slot for data storage. He managed to get it all to fit into a USB thumb drive enclosure, meaning that you can program it however you want in the Arduino IDE, then plug it into any USB port and let it run. This enables things like remote monitoring, asset tracking, and all kinds of spy-like activity.

One of the most unusual aspects of his project, though, is this line: “Everything came together very nicely and the height of parts and PCBs is exactly as I planned.” [Paul] had picked out an enclosure that was only supposed to fit a single PCB, but with some careful calculations, and picky component selection, he managed to fit everything onto two 2-layer boards that snap together with a connector and fit inside the enclosure.

We’ve followed [Paul’s] progress on this project with an earlier iteration of his GSM GPS Tracker, which used a Teensy and fit snugly into a handlebar, but this one is much more versatile.