From context clues, we can tell that [TVMiller] has been in and around NYC for some time now. He has observed a crucial weakness in the common metropolitan. Namely, they deafen themselves with earphones, leaving them senseless in a hostile environment.
To fix this problem, he came up with a simple hack, the metrophone. An ultrasonic sensor is hung from a backpack. The user’s noise making device of choice is plugged into one end, and the transducer into the other. When the metropolitan is approached from the rear by a stalking tiger or taxi cab, the metrophone will reduce the volume and allow the user to hear and respond to their impending doom. Augmentation successful.
The device itself consists of an off-the-shelf ultrasonic sensor, an Arduino, and a digital potentiometer. It all fits in a custom 3D printed enclosure and runs of two rechargeable coin cells. A simple bit of code scales the volume to the current distance being measured by the ultrasonic sensor once a threshold has been met.
In the video after the break, you can observe [TVMiller]’s recommended method for tranquilizing and equipping a metropolitan in its natural habitat without disturbing its patterns or stressing it unduly.
Continue reading “Hackaday Prize Entry: Ears On The Back Of Your Head”
Sometimes you start building, and the project evolves. Layers upon layers of functionality accrue, accrete, and otherwise just pile up. Or at least we’re guessing that’s what happened with [Varun Kumar]’s sweet “Surveillance Car Controlled by DTMF“.
In case you haven’t ever dug into not-so-ancient telephony, Dual-tone, multi-frequency signalling is what made old touch-tone phones work. DTMF, as you’d guess, encodes data in audio by playing two pitches at once. Eight tones are mapped to sixteen numbers by using a matrix that looks not coincidentally like the old phone keypad (but with an extra column). One pitch corresponds to a column, and one to a row. Figure out which tones are playing, and you’ve decoded the signal.
Anyway, you can get DTMF decoder chips for pennies on eBay, and they make a great remote-control interface for a simple robot, which is presumably how [Varun] got started. And then he decided that he needed a cell phone on the robot to send back video over WiFi, and realized that he could also use the phone as a remote controller. So he downloaded a DTMF-tone-generator app to the phone, which he then controls over VNC. Details on GitHub.
Continue reading “DTMF Robot Makes Rube Goldberg Proud”
It’s been a while since we’ve seen much action on the bristlebot front, which is too bad. So we’re happy to see [Extreme Electronics]’s take on the classic introductory “robot”: the Black Line Follower. The beauty of these things is their simplicity, so we’ll just point you to his build instructions and leave the rest to you.
The original bristlebot is a fantastic introduction to electronics, because it’s simple enough that you can cobble one together in no time. A battery, a pager motor, and a toothbrush head are all you need. But it goes where it wants, rather than where you want it to go.
Adding steering is as simple as tying two bristlebots together and firing one motor at a time to execute a turn. The Black Line Follower is of this style.
Of course, any good idea can be taken to extremes, as in this giant weight-shifting bristlebot, or this super-tiny IR-controlled bristlebot.
But that was more than five years ago now. What happened to the mighty engines of bristlebot creativity? Has the b-bot seen its finest hour? Or are we just waiting for the next generation to wiggle up to the plate?
Continue reading “Black Line Follower: A Modern Bristlebot”
This is what happens when you give Norwegian engineering students half a year to develop an ROV for their class.
The team utilized 3D printing to design and print their own thruster propellers and ducts for the ROV. It’s powered by HobbyKing motors with VESC speed controllers. This allows them to get from 0.6 to 30N of thrust from each propeller at 12V. Because of this accuracy they’re able to use a PID system to do automatic pitch, roll and depth control!
The electronics are housed in a 200mm acrylic tube (15mm wall thickness) with aluminum end caps and o-rings — an exact pressure rating is not given, but the team could flood the chamber with non-conductive oil to increase that even more — they just don’t need to for tests in a swimming pool. The undersea wire connectors they use (Subconn) are rated for 700 and 600 bar!
Continue reading “Subsea ROV has 6 degrees of Freedom + Autopilot”
[professor churlz] wrote in to let us know his results with modifying radio control ESCs (Electronic Speed Controllers) for use in a large (250lb range) BattleBot’s drivetrain. It’s a very long and involved build log entry that is chock-full of details and background.
If you want something spinning hard and fast, brushless is where it’s at. Brushless motors offer much better power-to-weight ratios compared to brushed DC motors, but some applications – like a large robot’s drivetrain – are less straightforward than others. One of the biggest issues is control. Inexpensive brushless motors are promising, but as [professor churlz] puts it, “hobby motor control equipment is not well suited for the task. Usually created for model airplanes, the controllers are lightly built, rated to an inch of the components’ lives using unrealistic methods, and usually do not feature reversing or the ability to maintain torque at low speeds and near-stall conditions, which is where DC motors shine.” Taking into account the inertia of a 243 lb robot is a factor as well – the controller and motor want to start moving immediately, but the heavy robot on the other side of it doesn’t. The answer was a mixture of hardware and firmware tweaking with a lot of testing.
Continue reading “Hacking R/C Brushless Motor Controllers for Use in Big Robots”
[Aldric Négrier] wrote in to let us know that his DriveMyPhone project has been open sourced. The project is a part telepresence, part remote-controlled vehicle, part robotic rover concept on which he says “I spent more time […] than I should have.” He has shared not just the CAD files, but every detail including tips on assembly. He admits that maybe a robotic chassis for a smartphone might not seem like a particularly new idea today, but it was “an idea with more potential” back in 2010 when he first started.
The chassis is made to cradle a smartphone. Fire up your favorite videoconferencing software and you have a way to see where you’re going as well as hear (and speak to) your surroundings. Bluetooth communications between the phone and the chassis provides wireless control. That being said, this unit is clearly designed to be able to deal with far more challenging terrain than the average office environment, and has been designed to not only be attractive, but to be as accessible and open to repurposing and modification as possible.
Continue reading “Smartphone-based Robotic Rover Project goes Open Source”
On the Starship Enterprise, an engineer can simply tell the computer what he’d like it to do, and it will do the design work. Moments later, the replicator pops out the needed part (we assume to atomic precision). The work [Raf Ramakers] is doing seems like the Model T ford of that technology. Funded by Autodesk, and as part of his work as a PhD Researcher of Human Computer Interaction at Hasselt University it is the way of the future.
The technology is really cool. Let’s say we wanted to control a toaster from our phone. The first step is to take a 3D scan of the object. After that the user tells the computer which areas of the toaster are inputs and what kind of input they are. The user does this by painting a color on the area of the rendering, we think this technique is intuitive and has lots of applications.
The computer then looks in its library of pre-engineered modules for ones that will fit the applications. It automagically generates a casing for the modules, and fits it to the scanned surface of the toaster. It is then up to the user to follow the generated assembly instructions.
Once the case and modules are installed, the work is done! The toaster can now be controlled from an app. It’s as easy as that. It’s this kind of technology that will really bring technologies like 3D printing to mass use. It’s one thing to have a machine that can produce most geometries for practically no cost. It’s another thing to have the skills to generate those geometries. Video of it in action after the break. Continue reading “RetroFab: Machine Designed Control of All the Things”