Probability-Based Drummer Leaves The Beats Up To Chance

July 23, 2019 by Erin Pinheiro No comments

Drum machines may seem like one of the many rites of passage for hardware makers, they’re a concept you can implement simply or take into the extreme making it as complex as you want. [Matt’s] DrumKid is one of them, and its long development history is wonderfully documented in the project logs.

[Matt’s] original intention was to use the automatic drummer as part of his band, wanting “the expressiveness of a good drummer but without the robotic tendencies of a simple drum machine”. For that, he created the first iteration of the DrumKid, a web-based project using the Web Audio API. The interface consisted of bars showing levels for different settings which could be intuitively tweaked, changing the probability of a drum sound being played. This gave the “drummer” its unpredictability, setting itself apart from any regular old drum machine.

Fast forward a few years, and [Matt] now wants to recreate his DrumKid as a proper piece of musical gear, porting the concept into a standalone hardware drum machine you can plug into your mixer. He decided to go with the Arduino framework for his project rather than the Teensy platform in order to make it cheaper to build. The controls are simplified down to a few buttons and potentiometers, and the whole thing runs off of three AAA batteries. Also, targeting the project for hardware like this allowed for new features to be added, such as a bit-crush filter.

We already saw the first prototype here on Hackaday when it was featured in a Hackaday Prize mentor session, and it’s nice to see how the project evolved since. After a number of revisions, the new prototype takes design cues from Teenage Engineering’s “Pocket Operator” drum machine, using the main PCB as its own faceplate rather than a 3D printed case in a familiar way we’ve seen before. Unfortunately, the latest board is non-functional due to a routing mistake, but you can see the previous working prototypes in his project logs.

A Drop-In Upgrade Module For Cheap Rotary Tools

July 22, 2019 by Tom Nardi 34 Comments

We’ve all seen them, the rotary tools that look almost, but not quite exactly, like a Dremel. They cost just a fraction of the real thing, and even use the same bits as the official Bosch-owned version. At first glance, they might seem like a perfect solution for the hacker who’s trying to kit out their workshop on a tight budget. There’s only one problem: the similarities between the two are only skin deep.

Recovering components from the original controller

As [Vitaly Puzrin] explains, one of the big problems with these clones are the simplistic electronics which have a tendency to stall out the motor at low RPM. So he’s developed a drop-in replacement speed controller for his particular Dremel clone that solves this problem. While the module design probably won’t work on every clone out there in its current form, he feels confident that with help from the community it could be adapted to other models.

Of course, the first step to replacing the speed controller in your not-a-Dremel is removing the crusty old one. But before you chuck it, you’ll need to recover a few key components. Specifically the potentiometer, filter capacitor, and the motor terminals. You could possibly source the latter components from the parts bin, but the potentiometer is likely going to be designed to match the tool so you’ll want that at least.

The microprocessor controlled upgrade board uses back EMF to detect the motor’s current speed without the need for any additional sensors; important for a retrofit module like this. [Vitaly] says that conceptually this should work on any AC brushed motor, and the source code for the firmware is open if you need to make any tweaks. But hacker beware, the current version of the PCB doesn’t have any AC isolation; you’ll need to take special care if you want to hook it up to your computer’s USB port.

On the other hand, if you’re willing to buy a cheap rotary tool just to crack it open and replace the electronics, you might as well just build your own. If you’re feeling particularly adventurous, you can always abandon the electric motor and spin it up with a tiny turbine. Continue reading “A Drop-In Upgrade Module For Cheap Rotary Tools” →

A Baseball Cap That Films The Past

July 21, 2019 by Lewin Day 17 Comments

The vast majority of cameras will start recording at the press of a button. This is perfectly acceptable behaviour if you wish to film something that hasn’t happened yet. If you want to film something that’s already over, you’re out of luck. [Johan Link] has built a camera designed to do just that, however, and put it on a cap.

The project consists of a Raspberry Pi 3B, combined with a 1080p USB webcam and a 5000 mAh power bank. These are attached to a baseball cap in order to shoot footage from the point of view of the wearer. The camera records continuously, saving the last 7 seconds of recorded video when the button is pressed — perfect for capturing things just after they’ve happened.

It’s a rolling record feature similar to that included with many dashcams and action cameras. Software is available on Github for those interested. While [Johan] has chosen a New York Yankees hat as the basis for the build, we’re confident it should work similarly well with your Seattle Seahawks cap. Raiders fans should contact the garment manufacturer.

A Multi-Layered Spin On Persistence Of Vision

July 20, 2019 by Roger Cheng 10 Comments

By taking advantage of persistence in human vision, we can use modest bits of hardware to create an illusion of a far larger display. We’ve featured many POV projects here, but they are almost always an exploration in two dimensions. [Jamal-Ra-Davis] extends that into the third dimension with his Volumetric POV Display.

Having already built a 6x6x6 LED cube, [Jamal] wanted to make it bigger, but was not a fan of the amount of work it would take to grow the size of a three-dimensional array. To sidestep the exponential increase in effort required, he switched to using persistence of vision by spinning the light source and thereby multiplying its effect.

The current version has six arms stacked vertically, each of which presents eight individually addressable APA102 LEDs. When spinning, those 48 LEDs create a 3D display with an effective resolution of 60x8x6.

We saw an earlier iteration of this project a little over a year ago at Bay Area Maker Faire 2018. (A demo video from that evening can be found below.) It was set aside for a while but has now returned to active development as an entry to Hackaday Prize 2019. [Jamal-Ra-Davis] would like to evolve his prototype into something that can be sold as a kit, and all information has been made public so others can build upon this work.

We’ve seen two-dimensional spinning POV LED display in a toy top, and we’ve also seen some POV projects taking steps into the third dimension. We like where this trend is going.

Continue reading “A Multi-Layered Spin On Persistence Of Vision” →

Hackaday Prize Mentor Session: Beau Ambur

July 19, 2019 by Gerrit Coetzee 4 Comments

Beau Ambur can often be found hosting hardware events and offering help all around the Bay Area. Now he’s turned it into a career and travels the west coast helping hackers and creators effectively leverage Kickstarter’s platform. Beau’s mentor session covers everything from, “is this project a good fit for venture capital?” to, “is open source a good fit for my project?”.

For this year’s Hackaday Prize we’ve found experts in a wide range of fields so you can take your entries to the next level regardless of the stage the project is in. The sessions are on a first come basis so sign up now for a chance to get some valuable feedback on your entry.

Your Robot Language Coach

The first project is a Personal English Trainer by the lonely programmer. As a student he noticed a need for a more interactive and portable language learning aid. Solutions do exist on the market but they are along the lines of a pocket dictionary, instructional phone app, or a full on translator. These break the flow of thought and conversation. The lonely programmer envisioned something that you can conversationally ask for help as you’re using a new language.

As many have discovered, the best way to see if there’s a need for something is to build a minimum viable product (MVP). The snips.ai platform offered the perfect foundation to quickly test out the idea. It’s working on a few words and he wants to get it ready for more people to play with the idea. The majority of the lonely programmer’s questions centered around making the project interesting for other hackers so that it could one day turn into a product.

Bolt-On Bike Assist

Rob and Shushanik are developing a project called BikeOn. It bolts to any bicycle and converts it to an electric assist bike without tools or replacing any components. BikeOn has already won some accolades such as Editors Choice at the last 2019 Makerfaire Bay Area. Rob had a few questions on how to transition a project from the proof of concept stage to the product stage. The discussion went over using open source as a tool for product promotion as well as getting funding for taking a hardware product to market.

He also wanted to know if there was anything the team could do to have a better shot at winning the prize. There were a few good tips such as directly focusing on the five categories the judges would be looking at: Concept, Design, Production, Benchmark, and Communication. It is also important to cover the development journey. Why did you make the choices you made when designing the project?

No-Spill Trash Can Concept

Rounding out this mentor session, Jeannie and her team of highschool students demonstrate SEAL. In the area around the Granada Hills Charter High School there are winds mighty enough to blow over full trashcans. This trash travels to the ocean and disrupts local ecosystems. The team is working on a device which can detect a tipping trashcan and keep the lid from opening.

Prototyping started with Arduinos, but they’ve already escalated to designing their own PCBs. Their hope is to produce a run of fifty devices and try them out with a local commercial partner. Beau recommended they look into the Micropython ecosystem. Not only would the students get the advantage of using the STM32 chips in their board layouts (reducing the number of support components they would need), micropython would make it easier for students to jump in and help rather than having to learn the nuances of C first.

The Hackaday Prize mentoring sessions continue through the summer so don’t forget to sign up and check out the list of mentors who are here to share their knowledge and experience.

Continue reading “Hackaday Prize Mentor Session: Beau Ambur” →

Getting Hackers Excited About Cable Robots

July 18, 2019 by Tom Nardi 22 Comments

Ever since he looked into them as a way to water and care for his plants, [Tom] has been fascinated with cable robots. These high-flying gadgets can move in three dimensions over huge areas, provided you’ve got the ability to string up the aforementioned cables. But despite their flexibility, there hasn’t been a whole lot of hobbyist level development with these unique systems.

With his entry into the 2019 Hackaday Prize, [Tom] is hoping to change that. He’s learned a lot by building his own cable robots, and now wants to take it to the next level. Ideally with collaboration from the community, if he can find other hackers looking to outfit their homes or workshops with their own miniature sky cranes.

So what can you do with a cable robot? In the video after the break, [Tom] shows one of his creations dutifully transporting beer cans across the room and stacking them into a pyramid. Admittedly this isn’t a particularly useful capability (unless you run a bar, perhaps), but it does show the speed and dexterity of the system even when crossing large distances. If you’ve ever wanted to play the home edition of “Automate the Freight”, this one’s for you.

The system uses a trio of 36 volt stepper motors powered by a homebrew SLA7078 driver that [Tom] designed himself. Each stepper turns a geared-down spindle to which a strong cable is attached. With some clever routing around the workspace, careful orchestration of these small winches can be used to move the point where all the cables meet in 3D space. All that’s left is mounting your gadget of choice to this central point, and away you go.

We’ve seen the concept used commercially, but as far as hobbyist projects go, the most activity we’ve seen in this space would have to be the various room sized 3D printers that have popped up over the years. It would be interesting to see what kind of interesting projects the community could come up with if they had something with a little more muscle.

Continue reading “Getting Hackers Excited About Cable Robots” →

3D Printed Prosthesis Reads Your Mind, Sees With Its Hand

July 17, 2019 by Erin Pinheiro 4 Comments

Hobbyist electronics and robotics are getting cheaper and easier to build as time moves on, and one advantage of that is the possibility of affordable prosthetics. A great example is this transhumeral prosthesis from [Duy], his entry for this year’s Hackaday Prize.

With ten degrees of freedom, including individual fingers, two axes for the thumb and enough wrist movement for the hand to wave with, this is already a pretty impressive robotics build in and of itself. The features don’t stop there however. The entire prosthesis is modular and can be used in different configurations, and it’s all 3D printed for ease of customization and manufacturing. Along with the myoelectric sensor which is how these prostheses are usually controlled, [Duy] also designed the hand to be controlled with computer vision and brain-controlled interfaces.

The palm of the hand has a camera embedded in it, and by passing that feed through CV software the hand can recognize and track objects the user moves it close to. This makes it easier to grab onto them, since the different gripping patterns required for each object can be programmed into the Raspberry Pi controlling the actuators. Because the alpha-wave BCI may not offer enough discernment for a full range of movement of each finger, this is where computer aid can help the prosthesis feel more natural to the user.

We’ve seen a fair amount of creative custom prostheses here, like this one which uses AI to allow the user to play music with it, and this one which gives its user a tattoo machine for an appendage.