ESP32 Rover With PCB Chassis Is Ready To Roll

March 2, 2020 by 12 Comments

The microcontrollers are cheap, the sensors are cheap, even the motors are cheap. So why are all the good wheeled robotics platforms so expensive? [Dimitris Platis] wanted to develop an affordable platform for experimenting with rovers, but the cheap plastic chassis he was using gave him all sorts of problems. So he did what any good hacker would do, and built a better version himself.

Interestingly, [Dimitris] decided to go with a chassis made from two PCB panels. The motors, mounted to small angled brackets, bolt directly to the lower PCB. These aren’t your standard $2 DC cans either. Each JGB37-520 gearhead motor comes complete with an encoder that allows your software to determine speed, distance, and direction. The upper PCB connects to the lower with several rows of pin headers, and plays host to whatever electronics payload you might be experimenting with at the time.

For the controller, [Dimitris] says the ESP32 is hard to beat by pretty much any metric you want to use. With integrated wireless and considerable computational power, there’s plenty of options for controlling your little rover either remotely or autonomously. But he also says that every effort has been made to ensure that you could switch out the microcontroller with something else should you want to spin up a customized version.

The whole idea reminds us a bit of quadcopters we’ve seen in the past, where the PCB wasn’t just being used structurally as a place to bolt the motors and hardware to, but actually contained functional traces and components that reduced how much wiring you needed to do. Naturally, this means that any damage to the chassis might cripple the electronics, but presumably, that’s what the big foam bumpers are there for.

[Dimitris] designed this project for educational use, so he assumes you’ll want to build 10 or 12 of these for your whole classroom. In those quantities, he says each bot will cost around $60. If you wanted to reduce the price a bit more, he says swapping the motors would be your best bet as they’re the single most expensive component of the design. That said, $60 for a quality open source rover platform sounds pretty fair to us.

Still too much? You could check out one of the 3D printable rover designs we’ve covered over the years. Or see if you can get lucky and pick up a cheap robot from the clearance rack and hack it.

3D Pens Can Make Ugly Drone Parts That Almost Work

January 5, 2020 by 23 Comments

Small hobby aircraft and light plastic parts go hand in hand, and a 3D printing pen makes lightweight plastic things without the overhead of CAD work and running a 3D printer. So could a 3D pen create useful plastic bits for small quadcopters? [Michael Niggel] decided to find out by building his drone parts with a 3D pen loaded with ABS plastic. He mostly discovered that the created objects could politely be said to look like they were sketched by a toddler, but that’s not all he learned.

He found that in general creating an object was harder than the marketing materials implied. As soon as the filament exits the pen’s nozzle, the thin little molten line of plastic cools rapidly and does two things: it has a tendency to curl, and loses its desire to stick to things. [Michael] found the whole affair worked much less like ‘drawing in thin air’ and rather more like piping frosting, or caulking.

An almost functional micro quad frame. The arms aren’t rigid enough to hold the motors vertical when under power.

Nevertheless, [Michael] sought to discover whether a 3D pen could be used to make quick and dirty parts of any use. He created two antenna brackets and one micro quad frame. All three are chaotic messes, but one antenna bracket was perfectly serviceable. The 3D pen was indeed able to create a strangely-shaped part that would have been a nightmare to CAD up. The other antenna part worked, but didn’t do anything a zip tie wouldn’t have done better. The rapid cooling of the plastic from the 3D pen has an advantage: extrusions don’t “droop” like a glob of hot glue does before it hardens.

By now, [Michael] agreed that the best way to create a plastic part of any complexity whatsoever seemed to be to draw sections flat, build them up in layers, then use the pen to weld the pieces together and add bulk. The micro quad frame he made in this way doesn’t look any nicer than the other attempts, but it did hold the parts correctly. Sadly, it would not fly. Once the motors powered up, the arms would twist and the flight controller was unable to compensate for motors that wouldn’t stay straight. This could probably be overcome, but while the end result was dirty it certainly wasn’t quick. The 3D pen’s niche seems restricted to simple, unstressed parts that aren’t permitted to gaze up themselves in a mirror.

If you have a 3D pen, we’d like to remind you of this mini spool design whose parts are welded together with the pen itself. For bigger jobs, a high-temperature hot glue gun can be used to dispense PLA instead.

Tiny Drones Navigate Like Real Bugs

November 6, 2019 by 14 Comments

When it comes to robotic navigation, the usual approach is to go as technically advanced and “smart” as possible. Yet the most successful lifeforms that we know of follow a completely different approach. With limited senses and cognitive abilities, the success of invertebrates like ants and honeybees lie in cooperation in large numbers. A joint team of researchers from TU Delft, University of Liverpool and Radboud University of Nijmegen, decided to try this approach and experimented with a simple navigation technique to allow a swarm of tiny flying robots to explore an unknown environment.

The drones used were of-the-shelf Crazyflie 2.0 micro quadcopters with add-on boards. Sensors consisted of it’s onboard IMU, simple range finding sensors on a Multi-ranger deck for obstacle detection, and a down pointing optical flow sensor, on a Flow deck, to keep track of the distance travelled.  To navigate, the drones used a “swarm gradient bug algorithm” (SGBA).  Each drone in has different preferred direction of travel from takeoff. When an obstacle encountered, it follows the contour of the obstacle, and then continues  in the preferred direction once the path is clear.  When the battery drops to 60%, it returns to a wireless homing beacon. While this technique might not be the most efficient, it has the major advantage of being “lightweight” enough to implement on a cheap microcontroller, an STM32F4 in this case. The full research article is available for free, and is a treasure trove of information.

The main application researchers have in mind is for search and rescue. A swarm of drones can explore an unstable or dangerous area, and identify key areas to focus rescue efforts on.  This can drastically reduce wasted time and risk to rescue workers. It is always cool to see complex problems being solved with simple solution, and we are keen to see where things go. Check out the video after the break. Continue reading “Tiny Drones Navigate Like Real Bugs” →

Coandă Effect Makes A Better Hovercraft Than A Quadcopter

October 17, 2019 by 22 Comments

Leaving no stone unturned in his quest for alternative and improbable ways to generate lift, [Tom Stanton] has come up with some interesting aircraft over the years. But this time he isn’t exactly flying, with this unusual Coandă effect hovercraft.

If you’re not familiar with the Coandă effect, neither were we until [Tom] tried to harness it for a quadcopter. The idea is that air moving at high speed across a curved surface will tend to follow it, meaning that lift can be generated. [Tom]’s original Coandă-copter was a bit of a bust – yes, there was lift, but it wasn’t much and wasn’t easy to control. He did notice that there was a strong ground effect, though, and that led him to design the hovercraft. Traditional hovercraft use fans to pressurize a plenum under the craft, lifting it on a low-friction cushion of air. The Coandă hovercraft uses the airflow over the curved hull to generate lift, which it does surprisingly well. The hovercraft proved to be pretty peppy once [Tom] got the hang of controlling it, although it seemed prone to lifting off as it maneuvered over bumps in his backyard. We wonder if a control algorithm could be devised to reduce the throttle if an accelerometer detects lift-off; that might make keeping the craft on the ground a bit easier.

As always, we appreciate [Tom]’s builds as well as his high-quality presentation. But if oddball quadcopters or hovercraft aren’t quite your thing, you can always put the Coandă effect to use levitating screwdrivers and the like.

Continue reading “Coandă Effect Makes A Better Hovercraft Than A Quadcopter” →

Hackaday Celebrates 15 Years And Oh How The Hardware Has Changed

September 5, 2019 by 56 Comments

Today marks exactly 15 years since Hackaday began featuring one Hack a Day, and we’ve haven’t missed a day since. Over 5,477 days we’ve published 34,057 articles, and the Hackaday community has logged 903,114 comments. It’s an amazing body of work from our writers and editors, a humbling level of involvement from our readers, and an absolutely incredible contribution to open hardware by the project creators who have shared details of their work and given us all something to talk about and to strive for.

What began as a blog is now a global virtual hackerspace. That first 105-word article has grown far beyond project features to include spectacular long-form original content. From our community of readers has grown Hackaday.io, launched in 2014 you’ll now find over 30,000 projects published by 350,000 members. The same year the Hackaday Prize was founded as a global engineering initiative seeking to promote open hardware, offering big prizes for big ideas (and the willingness to share them). Our virtual connections were also given the chance to come alive through the Hackaday Superconference, Hackaday Belgrade, numerous Hackaday Unconferences, and meetups all over the world.

All of this melts together into a huge support structure for anyone who wants to float an interesting idea with a proof of concept where “why” is the wrong question. Together we challenge the limits of what things are meant to do, and collectively we filter through the best ideas and hold them high as building blocks for the next iteration. The Hackaday community is the common link in the collective brain, a validation point for perpetuating great ideas of old, and cataloging the ones of new.

Perhaps the most impressive thing about the last 15 years of Hackaday is how much the technological landscape has changed. Hackaday is still around because all of us have actively changed along with it — always looking for that cutting edge where the clever misuse of something becomes the base for the next transformative change. So we thought we’d take a look back 15 years in tech. Let’s dig into a time when there were no modules for electronics, you couldn’t just whip up a plastic part in an afternoon, designing your own silicon was unheard of, and your parts distributor was the horde of broken electronics in your back room.

Continue reading “Hackaday Celebrates 15 Years And Oh How The Hardware Has Changed” →

2019 Cornell Cup Winners Include Autonomous Boat, Flapping UAV, And Leaping Rover

May 15, 2019 by 5 Comments

For college-aged engineers and designers, finding a problem they’re truly passionate about early on could very well set the trajectory for an entire career. This is precisely the goal of the Cornell Cup, a competition that tasks applicants with solving a real-world problem in a unique and interesting way. From what we saw this is definitely working, as teams showed up with ornithopter-based quadcopters, robotic dinghies, forest fire sniffers, and high-jumping rovers.

With such an open ended approach, individual entries have a tendency to vary wildly, running the gamut from autonomous vehicles to assistive technology. No team feels pressured to pursue a project they aren’t truly invested in, and everyone’s the better for it.

Given such lofty goals, Hackaday was proud to sponsor the 2019 Cornell Cup. Especially as it so closely aligns with the product design focus of this year’s Hackaday Prize. Designing something which solves a real-world problem is definitely part of the formula when the goal is to reach large scale production. And after seeing the entries first-hand during the Finals at Kennedy Space Center, we think every one of them would be a fantastic entry into the Hackaday Prize.

I don’t envy the judges who ultimately had to narrow it down to just a few teams to take home their share of the nearly $20,000 awarded. Join me after the break for a closer look at the projects that ended up coming out on top.

Continue reading “2019 Cornell Cup Winners Include Autonomous Boat, Flapping UAV, And Leaping Rover” →

Flying Sticks Are Now A Thing

April 29, 2019 by 24 Comments

Fixed-wing planes and helicopters are no longer the darling of the RC world. Even quadcopters and other multirotors are starting to look old hat, as the community looks to ever more outrageous designs. [rctestflight] has slimmed things down to the extreme with this coaxial bicopter build, also known as the Flying Stick (Youtube video, embedded below).

The initial design consists of two brushless outrunner motors fitted with props, rotating in opposite directions to cancel out their respective torques. Each is mounted on a gimbal, setup to provide control authority. iNav is used as a flight controller, chosen due to its versatile motor mixing settings. The craft was built to test its ability at recovery from freefall, as a follow-on from earlier attempts at building a brushless “rocket” craft.

Performance is surprisingly good for what is fundamentally two props on a stick. Initial tests didn’t quite manage a successful recovery, but the repaired single-gimbal version almost achieves the feat. Multirotors in general struggle with freefall recovery, so more research in this area is definitely worthwhile. Video after the break.

Continue reading “Flying Sticks Are Now A Thing” →