Hackaday Prize Entry: A 400MHz Modem

The Internet of Things has been presented as the future of consumer electronics for the better part of a decade now. Billions have been invested, despite no one actually knowing what the Internet of Things will do. Those billions need to go somewhere, and in the case of Texas Instruments, it’s gone straight into the next generation of microcontrollers with integrated sub-GHz radios. [M.daSilva]’s entry to the 2016 Hackaday Prize turns these small, cheap, radios into a portable communicator.

This ‘modem for the 400 MHz band’ consists simply of an ATmega microcontroller, TI’s CC1101 sub-GHz transceiver, an OLED display, and a UHF power amplifier. As far as radios radios go, this is as bare bones as it gets, but with the addition of a USB to serial chip and a small program this radio can send messages to anyone or anything in range. It’s a DIY pager with a couple chips and some firmware, and already the system works.

[M.daSilva] has two use cases in mind for this device. The first is an amateur radio paging system, where a base station with a big power amp transmits messages to many small modules. The second use is a flexible mdoule that links PCs together, using Ham radio’s data modes. With so many possibilities, this is one of the best radio builds we’ve seen in this year’s Hackaday Prize.

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A Fountain of Superhydrophobic Art

Superhydrophobic coating finds a new application in art through [Arthur Carabott] in the form of a bizarre fountain.

A Master’s student in the Global Innovation Design course at the London Royal College of Art, [Carabott] achieved the effect by leaving parts of the laser-cut acrylic untouched by Rust-oleum’s NeverWet Multisurface coating. A 3d printed spigot mounted high above the surface imparts greater velocity to the impacting water so as it hits the acrylic the liquid forms into channels giving the impression of something surreal. Indeed — his design is inspired by the optical illusions of Japanese mathematician Kokichi Sugihara which attempt to realize the impossible artwork of M.C. Escher. The effect is worthy of a double take.

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Autonomous Musical Soundscapes from 42 Fans and 7 Lasers

[dmitry] writes in to let us know about a new project that combines lasers with fans and turns the resulting modulation of the light beams into an autonomous soundscape. The piece is called “divider” and is a large, wall-mounted set of rails upon which seven red lasers are mounted on one end with seven matching light sensors mounted on the other end. Interrupting the lasers’ paths are forty-two brushless fans. Four Arduino Megas control the unit.

3Laser beams shining into light sensors don’t do much of anything on their own, but when spinning fan blades interrupt each laser beam it modulates the solid beams and turns the readings of the sensors on the far end into a changing electrical signal which can be played as sound. Light being modulated by fan blades to create sound is the operating principle behind a Fan Synth, which we’ve discussed before as being a kind of siren (or you can go direct to that article’s fan synth demo video to hear what kind of sounds are possible from such a system.)

This project takes this entire concept of a fan synth further by not only increasing the number of lasers and fans, but by tying it all together into an autonomous system. The lasers are interrupted repeatedly and constantly, but never simultaneously. Listen to and watch it in action in the video below.

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Foster a Robot, Explore Your Home Planet

The robots we’ve sent to explore other worlds in our stead are impressive feats of engineering. But stuck at the bottom of our gravity well as we are, they are fantastically expensive ventures that are out of reach of the DIY community. There’s still plenty to explore right in your own backyard, though, and this robot needs your help to explore planet Earth.

The project is called RoboSpatium, and it’s the brainchild of [Norbert Heinz]. The idea is a little like HitchBot except it will be sent from host to host by mail. (And it’s an actual robot, and not just brains in a bucket.) Hopefully each host will have something interesting for the robot to do for the 24 hours allotted, like explore a local landmark, get a robot-eye view of the goings on in a hackerspace, or just watch the sunset in some beautiful spot. Project participants will get to drive the robot via a web interface and do a little virtual exploration of a part of the world they might never otherwise get to see.

We gather that the robot in the video below is only a prototype at this point, and that the sensor suite and mechanicals have yet to be sorted out. Hackaday regulars will no doubt know [Norbert] better as the excellently accented [HomoFaciens], creator of dumpster-sourced CNC machines, encoders made from tin can lids and wheels of resistors, and a potentially self-replicating CNC plotter. [Norbert] has the hacker chops to pull this off, and we think it’s a pretty neat idea with the potential to engage and educate a lot of people. We think it could do with a little support from the Hackaday community.

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Taming Robot Arm Jump with Accelerometers

Last fall, I grabbed a robot arm from Robot Geeks when they were on sale at Thanksgiving. The arm uses servos to rotate the base and move the joints and gripper. These work well enough but I found one aspect of the arm frustrating. When you apply power, the software commands the servos to move to home position. The movement is sufficiently violent it can cause the entire arm to jump.

This jump occurs because there is no position feedback to the Arduino controller leaving it unable to know the positions of the arm’s servos and move them slowly to home. I pondered how to add this feedback using sensors, imposing the limitation that they couldn’t be large or require replacing existing parts. I decided to try adding accelerometers on each arm section.

Accelerometers, being affected by gravity when on a planet, provide an absolute reference because they always report the direction of down. With an accelerometer I can calculate the angle of an arm section with respect to the direction of gravitational acceleration.

Before discussing the accelerometers, take a look at the picture of the arm. An accelerometer would be added to each section of the arm between the controlling servos.

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Minecraft Trojan Horse Teaches Kids to Love Electronics and Code

Kids love Minecraft, and a clever educator can leverage that love to teach some very practical skills. The summer class offered by the Children’s Museum in Bozeman Montana would have blown my mind if such a thing existed when we were younger. (Rather than begging one of the dads in my Boy Scout Troop to pirate Visual Studio for me, which was delivered in the form of an alarmingly tall stack of CDs.) The kids in Bozeman get to learn hardware, software, their integration, and all while playing Minecraft.

Minecraft is an immersive universe that has proven to suck in creative minds. It’s the bait that pulls the kids into the summer class but Serialcraft delivers on making the learning just as addictive. This is accomplished by providing students with physical objects that are tied to the Minecraft world in meaningful ways we just haven’t seen before (at least not all at one time). On the surface this adds physical LEDs, toggle switches, potentiometers, and joysticks to the game. But the physical controls invite understanding of the mechanisms themselves, and they’re intertwined in exciting ways, through command blocks and other in-game components that feel intuitive to the students. From their understanding of the game’s mechanics they understand the physical objects and immediately want to experiment with them in the same way they would new blocks in the game.

The thing that makes this magic possible is a Minecraft mod written by [John Allwine], who gave us a demonstration of the integration at Maker Faire Bay Area 2016. The mod allows the user to access the inputs and output of the Arduino, in this case a Pololu A-Star 32U4, from within Minecraft. For the class this is all packaged nicely in the form of a laser cut controller. It has some LEDs, two joysticks, buttons, potentiometers, and a photosensor.

As you can see in the video below the break, it’s really cool. The kids have a great time with it too. For example, [John] showed them how they can attach their unique controller to a piston in the world. Since this piston can be controlled by them alone, they quickly figured out how to make secret safe rooms for their items.

Another troublesome discovery, was that the photo transistor on the controller set the light level in the game world by altering the time of day. Kids would occasionally get up and change the world from day to night, by turning the lights in the room on or off. A feature that has a certain appeal for any Minecraft player, is rigging one of the LEDs on the controller to change brightness depending on proximity to a creeper.

There’s a lot more to the library, which is available on GitHub. The kids (and adults) have a great time learning to link the real world with the world’s most accessible fantasy world creation kit.  Great work [John]!

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Driving BB-8: More Than One Way to Move this Bot

BB-8 is the much loved new droid introduced in the 2016 movie Star Wars: The Force Awakens, though in my case from the very first trailer released in 2014 I liked it for the interesting engineering problems it posed. How would you make a robot that’s a ball that rolls along, but with a head that stays on top while the ball rolls under it?

To make the ball roll, the answer most people found obvious at first was to use the analogy of a hamster wheel. The hamster running inside makes the wheel turn. In the BB-8 building world, which is quite large, the drive mechanism has come to be called a hamster drive, or just a hamster.

Magnets holding the head on
Magnets holding the head on

For the head, it seemed obvious that there would be magnets inside the ball, perhaps held in place near the top of the ball by a post extending up from the hamster. Corresponding magnets in attraction would then be attached to the underside of the head, and balls (also mounted under the head) would keep the head moving smoothly over the ball.

The magnet approach for the head has turned out to be the method used by all BB-8 builders that I’ve seen. However, the hamster has turned out to be only one of multiple solutions. Since the original debut many different methods have been used in builds and we’re going to have a lot of fun looking at each separate approach. It’s almost like revealing a magic trick; but really it’s all just clever engineering.

Note that for the actual movie, a combination of 7 or 8 props and CGI were used. The official working BB-8s that are shown at various promotional events were built after the movie was made and as of this writing, few details of their construction have been released. One notable detail, however, is that they aren’t using hamster drives.

Below are details of all the different BB-8 drive systems I’ve seen so far that have been built along with how they work.

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