A Better Motor For Chickenwalkers

The last decade or so has seen remarkable advances in motor technology for robotics and hobby applications. We’re no longer stuck with crappy brushed motors, and now we have fancy (and cheap!) stepper motors, brushless motors for drones, and servo motors. This has led to some incredible achievements; drones are only barely possible with brushed motors, and you can’t build a robot without encoders.

For his entry into the Hackaday Prize, [Gabrael Levine] is taking on one of the hardest robotics challenges around: the bipedal robot. It’s a chickenwalker, or an AT-ST; either way, you need a lot of power in a very small space, and that’s where the OpenTorque Actuator comes in. It’s a quasi-direct-drive motor that was originally pioneered by the MIT Biomimetics Lab.

The key feature of the OpenTorque Actuator is using a big brushless motor, a rotation encoder, and a small, 8:1 planetary gear set. This allows the motor to be backdrivable, capable of force-sensing and open-loop control, and because this actuator is 3D printed, it’s really cheap to produce.

But a motor without a chassis is nothing, and that’s where the Blackbird Bipedal Robot comes in. In keeping with best practices of robotic design, the kinematics are first being tested in simulation, with the mechanical build happening in parallel. That means there’s some great videos of this chickenwalker strutting around (available below), and so far, everything looks great. This bipedal robot can turn, walk, yaw, and work is continuing on the efforts to get this bird-legged bot to stand still.

Bunnie Huang Talks Manufacturing And Component Choices During Hackaday Prize Mentoring Session

Andrew “Bunnie” Huang’s mentor session for the Hackaday Prize shows off the kind of experience and knowledge hard to come by unless you have been through the hardware development gauntlet countless times. These master-classes match up experts in product development with Prize entrants working to turn their projects into products. We’ve been recording them so that all may benefit from the advice and guidance shared in each session.

The appealing little FunKey pocket gaming platform.
The appealing little FunKey pocket gaming platform.

Bunnie is someone who is already familiar to most Hackaday readers. His notoriety in our community began nearly two decades ago with his work reverse engineering the original Microsoft X-box, and he quickly went on to design (and hack) the Chumby Internet appliance, he created the Novena open-source laptop, and through his writing and teaching, he provides insight into sourcing electronic manufacture in Shenzhen. He’s the mentor you want to have in your corner for a Hackaday Prize entry, and that’s just what a lucky group had in the video we’ve placed below the break.

While this session with Bunnie is in the bag it’s worth reminding you all that we are still running mentor sessions for Hackaday Prize entrants, so sign up your entry for a chance to get some great feedback about your project.

The first team to meet with Bunnie are FunKey, whose keychain Nintendo-like handheld gaming platform was inspired by a Sprite_tm project featuring a converted novelty toy. The FunKey team have produced a really well-thought-out design that is ready to be a product, but like so many of us who have reached that point they face the impossible hurdle of turning it into a product. Their session focuses on advice for finding a manufacturing partner and scaling up to production.

A prototype HotorNot Coffee Stirrer, showing their problem of having to maintain food-safe components.
A prototype HotorNot Coffee Stirrer, showing their problem of having to maintain food-safe components.

HotorNot Coffee Stirrer is trying to overcome a problem unique to their food-related project. A hot drink sensor that has to go in the drink itself needs to be food safe, as well as easy enough to clean between uses. A variety of components are discussed including a thermopile on a chip that has the advantage of not requiring contact with the liquid, but sometimes the simplest ideas can be the most effective as Bunnie reminds us that a cheap medical thermometer teardown can tell us a lot about appropriate parts for this application.

The idea behing PhalangePad is an attractive one, but making those sensors reliable is no trivial eercise.
The idea behing PhalangePad is an attractive one, but making those sensors reliable is no trivial eercise.

It’s another component choice problem that vexes PhalangePad, an input device that relies on the user tapping the inside of their fingers with their thumb. It’s a great idea, but how should these “keypresses” be detected? Would you use a capacitive or magnetic sensor, a force sensitive resistors, or maybe even machine vision? Here Bunnie’s encyclopaedic knowledge of component supply comes to the fore, and the result is a fascinating insight into the available technologies.

We all amass a huge repository of knowledge as we pass through life, some of the most valuable of which is difficult to pass on in a structured form and instead comes out as incidental insights. An engineer with exceptional experience such as Bunnie can write the book on manufacturing electronics in China but still those mere pages can only scratch the surface of what he knows about the subject. There lies the value of these mentor sessions, because among them the gems of knowledge slip out almost accidentally, and if you’re not watching, you’ll miss them.

This is the second in our series of Hackaday Prize mentoring sessions this year, but we have more already in the can and further sessions to record. We’re constantly looking for more participants though, so make sure if you haven’t already that you put your entry in for Hackaday Prize and check out the list of mentors who are here to share their knowledge and experience. Continue reading “Bunnie Huang Talks Manufacturing And Component Choices During Hackaday Prize Mentoring Session”

Finally, An Open Source Multimeter

For his Hackaday Prize entry, [Martin] is building an Open Source Multimeter that can measure voltage, current, and power. It’s an amazing build, and you too can build one yourself.

The features for this multimeter consist of voltage mode with a range of +/-6V and +/-60V. There’s a current mode, basically the same as voltage, with a range of +/-60 mA and +/-500mA. Unlike our bright yellow Fluke, there’s also a power mode that measures voltage and current at the same time, with all four combinations of ranges available. There’s a continuity test that sounds a buzzer when the resistance is below 50 Ω, and a component test mode that measures resistors, caps, and diodes. There’s a fully isolated USB interface capable of receiving commands and transmitting data, a real-time clock, and in the future there might be frequency measurement.

This build is based on the STM32F103 microcontroller, uses an old Nokia phone screen, and unlike so many other multimeters, this thing is small. It’s very small. More than small enough to fit in your pocket and forget about it, unlike nearly every other multimeter available. There’s one thing about multimeters, and it’s that the best multimeter is the one that you have in your hands when you need it, and this one certainly fits the bill.

The entire project is being written up on hackaday.io, there’s a GitHub repo for all the hardware and software, and there’s also a video demo covering all the features (available below). This is a stand-out project, and something we desperately want to get our hands on.

Continue reading “Finally, An Open Source Multimeter”

Trash Printer Directly Uses Recycled Plastics

3D printing is all well and good, but it can get expensive having to purchase roll after roll of filament. Various projects exist that attempt to take unwanted 3D prints and turn them back into filament to be used again. However, [Sam Smith] took a different path. The Trash Printer is a 3D print head that works with recycled plastic, with less intermediate processing steps.

The Trash Printer is a print head is intended to work with shredded plastics directly, rather than by first turning them back into a filament. Thus far, [Sam] has tested the Polypropylene and HDPE, and results are promising. While the prints aren’t of the same quality as using pre-prepared filament, the parts are still viable and fit for purpose.

The print head consists of an auger, along with a cartridge heater, which work together to push plastic to the print head. The head is constructed out of laser-cut parts and a few off-the-shelf components, making it easy to replicate. [Sam] has spent significant time honing the design, and has several ideas for ways in which it could be developed further. We’re eager to see how far this technology can go, and can’t wait to see what comes next. We’ve seen other attempts to recycle plastics for 3D printing, too. Expect to see further developments in this space coming thick and fast.

Tiny Tank Inspects Your Crawlspace

If you’ve got some drone or FPV part lying around, this is the build for you. It’s a remote controlled tank, with a camera and video transmitter, that’s only 65 mm x 40 mm x 30 mm in size. Why on Earth would you ever build something so small? You can look around in your crawlspace, I guess. Any way you look at, this thing is tiny.

The tank has traditional tank skid steering through two brushless motors. The battery is one cell, as that’s just about the largest battery you can put in a vehicle so small, and the camera is just off-the-shelf quadcopter stuff set into a 3D printed enclosure. There are a few LEDs for lights. Other than that, it’s just so tiny and so cute.

The builder behind this tank, [honnnest], put up a video going through the build and demonstrating what kind of video you can expect from a tank this small. It’s a bit fast for a tank, and that’s not even considering the scale effects, but if the chassis is 3D printed, you can always print a few reduction gears, too.

Continue reading “Tiny Tank Inspects Your Crawlspace”

DIY Raspberry Pi Multi FX Stomp Box

From building your own analog effects pedal to processing audio through micro controllers, a lot of musicians love building their own boxes of sound modification. In his entry for the 2019 Hackaday Prize, [Craig Hissett] has a project to build an all-in-one multi-effects stomp box.

At the center of the box is a Raspberry Pi with an AudioInjector stereo sound card.  The card takes care of stereo in and out, and passing the signal to the Pi. The software is Modep, an open source audio processor that allows the setup of a chain of digital effects plugins to be run on the Pi. After finding some foot switches, [Craig] connected them to an Arduino Pro Micro which he set up as a MIDI device that sends MIDI messages to the Modep software running on the Pi.

There are still a few steps to go, but [Craig] has the basic layout covered. Next up is wiring it up and building a proper case for it, as well as working on latency. A few years ago, another multi-effects stomp box was featured in the Hackaday Prize, and last year, this multi-effects controller was featured.


Simulating The Enigma’s Oddball Cousin

Even if you wouldn’t describe yourself as a history buff, you’re likely familiar with the Enigma machine from World War II. This early electromechanical encryption device was used extensively by Nazi Germany to confound Allied attempts to eavesdrop on their communications, and the incredible effort put in by cryptologists such as Alan Turing to crack the coded messages it created before the end of the War has been the inspiration for several books and movies. But did you know that there were actually several offshoots of the “standard” Enigma?

For their entry into the 2019 Hackaday Prize, [Arduino Enigma] is looking to shine a little light on one of these unusual variants, the Enigma Z30. This “Baby Enigma” was intended for situations where only numerical data needed to be encoded. Looking a bit like a mechanical calculator, it dropped the German QWERTZ keyboard, and instead had ten buttons and ten lights numbered 0 through 9. If all you needed to do was send off numerical codes, the Z30 was a (relatively) small and lightweight alternative for the full Enigma machine.

Creating an open source hardware simulator of the Z30 posses a rather unique challenge. While you can’t exactly order the standard Enigma from Digi-Key, there are at least enough surviving examples that they’ve been thoroughly documented. But nobody even knew the Z30 existed until 2004, and even then, it wasn’t until 2015 that a surviving unit was actually discovered in Stockholm.

Of course, [Arduino Enigma] does have some experience with such matters. By modifying the work that was already done for full-scale Enigma simulation on the Arduino, it only took a few hours to design a custom PCB to hold an Arduino Nano, ten buttons with matching LEDs, and of course the hardware necessary for the iconic rotors along the top.

The Z30 simulator looks like it will make a fantastic desk toy and a great way to help visualize how the full-scale Enigma machine worked. With parts for the first prototypes already on order, it shouldn’t be too long before we get our first good look at this very unique historical recreation.