The Raspberry Pi and other similar Linux-based single board computers simplify many projects. However, one issue with Linux is that it doesn’t like being turned off abruptly. Things have gotten better, and you can certainly configure things to minimize the risk, but–in general–shutting a Linux system down while it is running will eventually lead to file system corruption.

If your project has an interface, you can always provide a shutdown option, but that doesn’t help if your application is headless. You can provide a shutdown button, but that leaves the problem of turning the device back on.

[Ivan] solved this problem with–what else–an Arduino (see the video below). Simplistically, the Arduino reads a button and uses a FET to turn off the power to the Pi. The reason for the Arduino, is that the tiny processor (which draws less than a Pi and doesn’t mind being shut down abruptly) can log into the Pi and properly shut it down. The real advantage, though, is that you could use other Arduino inputs to determine when to turn the Pi on and off.

For example, it is easy to imagine a Pi in an automotive application where the Arduino would sense the ignition was off for a certain period of time and then go ahead and shut off the Pi. Or maybe the Pi needs to be turned on when a motion sensor fires and then turned off again once there is no motion for a particular time period. Any of these strategies would be simple to build with the Arduino.

We’ve seen a similar project that used an IR remote as the trigger instead of a physical button. If you are afraid the Pi will just lose power unexpectedly, you might consider a battery backup. If powering a Pi with regular electricity is too tame for you, try steam.

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The idea in short:
I will send a robot around planet earth. The robot will be sent to you free of charge. Let it run in your area for 24h and show all earthlings your projects or a piece of your country. Send the rover to the next destination after your mission is over (postal charges will be refunded).
The robot can be controlled through a web interface while transmitting a live video stream. All young scientist and of course all discoverers that are young at heart get free access to the robots, there is even no registration needed.

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The Shower Thoughts subreddit is a collection of all those ideas or philosophical questions that race through your mind while in the bathroom. For example, “I like to think money wouldn’t change me; yet when I’m winning Monopoly I’m a terrible person,” or “12 years ago leaving CDs out in my car gave theives a reason to break in. Today, leaving CDs out is a deterrent.”

While most folks would simply browse Reddit on their phones or laptops, Harin De Mel decided to something a bit different. He managed to hack his vehicle’s dashboard to display some of the best thoughts from the last hour. Not a bad idea for when you’re stuck in traffic or sitting in the car waiting for someone to come outside, right?

The Maker sniffed the CAN bus on his 2012 Hyundai Genesis, and isolated the LCD from the rest of the network. He used Raspberry Pi and an Arduino, both of which are interfaced with an MCP2515 — one for the display, the other to receive signals from the original network. A Wi-Fi dongle on the Raspberry Pi enables Internet connectivity.

De Mel was also able to make the text scroll, which was accomplished through the CAN bus. However, Python script on the Raspberry Pi provided more control on how fast or frequently the message would come across the screen.

Now that I have a better understanding of how the LCD is controlled, I want to use the screen for more useful information. I have an in-dash Nexus 7 and would like to parse the information of the currently playing track to the car’s system as if it was an iPod. Frank Zhao was kind enough to leave a comment on my previous post pointing me in the direction of the Apple Accessories Protocol (AAP) which I will also begin to tinker with at some point in the future.

The code for the project is available on GitHub, and you can read more about the build on his blog. In the meantime, check out the video below to see it all in action.

Harin De Mel could have hacked his car to display something "useful", but where's the challenge in that? Shower thoughts, it is!

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Do you dream of developing a hot, new hardware gadget and bringing it to market? Maybe your goal is to make the world better with your product, or perhaps you just want to get filthy rich selling your product. Developing a project prototype using an Arduino, Raspberry Pi, or other […]

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The post Turn Your Electronics Project into a Sellable Product appeared first on Make: DIY Projects and Ideas for Makers.

[burgerga] loves attending Music Festivals. He’s also a MechE who loves his LED’s. He figured he needed to put it all together and do something insane, so he build a huge, 15″ geodesic sphere containing 540 WS2812B addressable LED’s. He calls it the SOL CRUSHER. It sips 150W when all LED’s are at full intensity, making it very, very, bright.

As with most WS2812B based projects, this one too is fairly straightforward, electrically. It’s controlled by four Teensy 3.2 boards mounted on Octo WS2811 adapter boards. Four 10,000 mAh 22.2V LiPo batteries provide power, which is routed through a 5V, 30Amp heatsinked DC-DC converter. To protect his LiPo batteries from over discharge, he built four voltage monitoring modules. Each had a TC54 voltage detector and an N-channel MOSFET which switches off the LiPo before its voltage dips below 3V. He bundled in a fuse and an indicator, and put each one in a neat 3D printed enclosure.

The mechanical design is pretty polished. Each of the 180 basic modules is a triangular PCB with three WS2812B’s, filter capacitors, and heavy copper pours for power connections. The PCB’s are assembled in panels of six and five units each, which are then put together in two hemispheres to form the whole sphere. His first round of six prototypes set him back as he made a mistake in the LED footprint. But it still let him check out the assembly and power connections. For mechanical support, he designed an internal skeleton that could be 3D printed. There’s a mounting frame for each of the PCB panels and a two piece central sphere. Fibreglass rods connect the central sphere to each of the PCB panels. This lets the whole assembly be split in to two halves easily.

It took him over six months and lots of cash to complete the project. But the assembly is all done now and electrically tested. Next up, he’s working on software to add animations. He’s received suggestions to add sensors such as microphones and accelerometers via comments on Reddit. If you’d like to help him by contributing animation suggestions, he’s setup a Readme document on Dropbox, and a Submission form. Checkout the SolCrusher website for more information.

Thanks [Vinny Cordeiro], for letting us know about this build.

Jochen Maria Weber’s Foxes Like Beacons is an exploratory project using open data of public radio stations with inexpensive, low-power signal detection in order to create an open positioning system. According to the designer:

Today’s satellite based GPS enable and augment uncountable everyday processes, ranging from logistics to fitness trackers and even intimate dating applications. These proprietary systems are mostly invisibly controlled and curated by governments, military and economic actors. Since GPS ubiquitously affect our interactions and experiences with our environment, economy and privacy, Foxes Like Beacons questions this present model, thus opening up space for speculations about alternative navigation systems and new models for interaction.

Open data about public radio stations, transceivers and open source signal detection can be used to calculate geo positions.

So, Jochen developed three example devices based on the same technical structure using very low-power, open and off-the-shelf technology. This consists of an omnidirectional antenna, a 4.3″ TFT screen, a compass, gyroscope and barometric altitude sensor, a radio frequency tuner, a battery, an Arduino Nano (for signal processing), and a Rasperry Pi 2.

Precision and miniaturization can be extremely increased using customized parts, and by building on the distributed infratructure of public broadcast radio, Foxes Like Beacons is not subject to any kind of central control or curation.

First, Device No.1 measures the received signal strengths and decodes the identifiers of minimum three stations. Open data about their transceiver locations and respective transmission power is used to calculate distance to each transceiver and which can therefore be triangulated, in order to get a users geo location. Incorporating more stations leads to a higher resolution and more accurate geo locations.

Next, Device No.2 enables users to navigate by pleasing of sound rather than geographical information, following “geo-acoustic” maps. It automatically adjusts the volumes of simultaneously played stations according to proximity.

Finally, Device No.3 speculates about further applications by analyzing and interpreting signal modulations which occur due to factors like electromagnetic radiation, weather, and geographic conditions. These modulate radio signals in characteristc ways which can be interpreted and incorporated in navigation/exploration.

Foxes Like Beacons is part of the ongoing project “Stupid, Messy Networks,” which investigates the process of digital networks becoming ubiquitous infrastructures and moreover how these new infrastructures empower or constrain actors in economical, political and social interactions.

(via Creative Applications)

For Hackers, rapid prototyping is made easier using basic building blocks such as the Raspberry Pi, Arduino and the huge variety of add on shields for home brew projects. But we don’t see too many real world Industrial applications or machines built using these off-the-shelf electronics. [SlyScience] built The Green Machine – an industrial grade, automated spray painting device to help coat polycarbonate tubes consistently.

The Green Machine is essentially a linear drive that can move a spray gun across a spinning clear tube and coat it evenly with the desired color. These tubes are used as color filters – they slide over standard T5, T8 or T12 fluorescent lamps – and are used in advertising, special effects, films and similar applications. For almost 10 years prior to this machine, the task was done manually. The HPLV (high pressure, low volume) spray gun used for this process needed skilled hands to get consistent results. It was easy to ruin a tube and cleaning them was not possible. [SlyScience] figured things out on the go – teaching himself and figuring out all of the software and hardware pieces of the puzzle. The welded steel frame is about the only “custom” part in this build. Everything else is COTS. Check out the video of The Green Machine in action below, and if you have any tips to help improve the build, chime in with your comments.

The subreddit for Shower Thoughts offers wisdom ranging from the profound to the mundane. For example: “Every time you cut a corner you make two more.” Apparently, [Harin] has a bit of an addiction to the subreddit. He’s been sniffing the CAN bus on his 2012 Hyundai Genesis and decided to display the top Shower Thought on his radio screen.

To manage the feat he used both a Raspberry Pi and an Arduino. Both devices had a MCP2515 to interface with two different CAN busses (one for the LCD display and the other for control messages which carries a lot of traffic.

The code is available on GitHub. There’s still work to do to make the message scroll, for example. [Harin] has other posts about sniffing the bus, like this one.

We’ve covered CAN bus quite a bit, including some non-automotive uses. We’ve even seen the CAN bus for model railroading.

Calvin Cherry has created a wearable instrument programmed to respond to body movement. The Maker, who is a grad student at the University of Wisconsin-Madison, calls his device “Music from Motion,” or “mFM.” It consists of small electronic sensors Velcro-ed onto his wrists and ankles that, with every move, alter a synthesized track playing on a loop over a set of speakers.

Various motions correspond to different sounds. For instance, increasing the pace with his left foot adds more drum. Picking up the movement with his right foot throws in a cymbal. When he rotates his right hand, it makes the track a bit woozier through an audio mixing process called flanging. When he moves his left hand, it prompts a wah-wah effect.

And what would a musician be without his or her fans? Cherry points out that there are specific triggers, including an audio clip of a roaring crowd whenever he claps his hands. According to a recent article, there’s a monitor that displays real-time information on the music — an interface he devised with Pure Data.

At the heart of the project lies a Raspberry Pi and Arduinos. An Arduino on the sensor receives data relating to how quickly the body parts are accelerating, and wirelessly sends that information over radio to a small device housed inside a LEGO case. That receiver features a Raspberry Pi that translates the acceleration data into an output — the changes in the audio itself.

Cherry hopes to make mFM open-source in the near future, so he could see what other Makers are able to do with it. You can read all about the project here.

(Photo: Saiyna Bashir / The Capital Times)