ESP32 Rover With PCB Chassis Is Ready To Roll

March 2, 2020 by Tom Nardi 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.

Faux Cow Munches Faux Grass On A Faux Roomba

October 24, 2019 by Anool Mahidharia 13 Comments

Out in the countryside, having a cow or to two wouldn’t be a big deal. You can have a cattle shed full of them, and no one will bat an eyelid. But what if you’re living in the big city and have no need of pet dogs or cats, but a pet cow. It wouldn’t be easy getting it to ride in the elevator, and you’d have a high chance of being very, very unpopular in the neighbourhood. [Dane & Nicole], aka [8 Bits and a Byte] were undaunted though, and built the Moomba – the Cow Roomba to keep them company in their small city apartment.

The main platform is built from a few pieces of lumber and since it needs to look like a Roomba, cut in a circular shape. Locomotion comes from two DC geared motors, and a third swivel free wheel, all attached directly to the wooden frame. The motors get their 12V juice from eight “AA” batteries. The free range bovine also needs some smarts to allow it to roam at will. For this, it uses a Raspberry Pi powered by a power bank. The Pi drives a 2-channel relay board which controls the voltage applied to the two motors. Unfortunately, this prevents the Moomba from backing out if it gets stuck at a dead end. For anyone else trying to build this it should be easy enough to fix with an electronic speed controller or even by adding a second 2-channel relay board which can reverse the voltage applied to the motors. The Moomba needs to “Moo” when it feels like, so the Raspberry Pi streams a prerecorded mp3 audio clip to a pair of USB speakers.

If you see the video after the break, you’ll notice that making the Moomba sentient is a simple matter of doing “ctrl+C” and “ctrl+V” and you’re good to go. The python code is straight forward, doing one of four actions – move forward, turn left, turn right or play audio. The code picks a random number from 0 to 3, and then performs the action associated with that number. Finally, as an added bonus, the Moomba gets a lush carpet of artificial green grass and it’s free to roam the range.

At first sight, many may quip “where’s the hack” ? But simple, easy to execute projects like these are ideal for getting younglings started down the path to hacking, with adult supervision. The final result may appear frivolous, but it’ll excite young minds as they learn from watching.

Continue reading “Faux Cow Munches Faux Grass On A Faux Roomba” →

India’s Moon Mission Is Far From Over

September 17, 2019 by Tom Nardi 19 Comments

India’s Chandrayaan-2 mission to the Moon was, in a word, ambitious. Lifting off from the Satish Dhawan Space Centre on July 22nd, the mission hoped to simultaneously deliver an orbiter, lander, and rover to our nearest celestial neighbor. The launch and flight to the Moon went off without a hitch, and while there were certainly some tense moments, the spacecraft ultimately put itself into a stable lunar orbit and released the free-flying lander so it could set off on its independent mission.

Unfortunately, just seconds before the Vikram lander touched down, an anomaly occurred. At this point the Indian Space Research Organisation (ISRO) still doesn’t know exactly what happened, but based on the live telemetry stream from the lander, some have theorized the craft started tumbling or otherwise became unstable between three and four kilometers above the surface.

Telemetry indicates a suboptimal landing orientation

In fact, for a brief moment the telemetry display actually showed the Vikram lander completely inverted, with engines seemingly accelerating the spacecraft towards the surface of the Moon. It’s unclear whether this was an accurate depiction of the lander’s orientation in the final moments before impact or a glitch in the real-time display, but it’s certainly not what you want to see when your craft is just seconds away from touchdown.

But for Chandrayaan-2, the story doesn’t end here. The bulk of the mission’s scientific goals were always to be accomplished by the orbiter itself. There were of course a number of scientific payloads aboard the Vikram lander, and even the Pragyan rover that it was carrying down to the surface, but they were always secondary objectives at best. The ISRO was well aware of the difficulties involved in making a soft landing on the Moon, and planned their mission objectives accordingly.

Rather than feel sorrow over the presumed destruction of Vikram and Pragyan, let’s take a look at the scientific hardware aboard the Chandrayaan-2 orbiter, and the long mission that still lies ahead of it.

Continue reading “India’s Moon Mission Is Far From Over” →

A 4G Rover And The Benefits Of A Shakedown Mission

September 12, 2019 by Lewin Day 16 Comments

Many moons ago, in the shadowy darkness of the 1990s, a young Lewin visited his elder cousin. An adept AMOS programmer, he had managed to get his Amiga 500 to control an RC car, with little more than a large pile of relays and guile. Everything worked well, but there was just one problem — once the car left the room, there was no way to see what was going on.

Why don’t you put a camera on it? Then you can drive it anywhere!

—Lewin

This would go on to inspire the TKIRV project approximately 20 years later. The goal of the project is to build a rover outfitted with a camera, which is controllable over cellular data networks from anywhere on Earth. For its upcoming major expedition, the vehicle is to receive solar panels to enable it to remain operable in distant lands for extended periods without having to return to base to recharge.

The project continues to inch towards this goal, but as the rover nears completion, the temptation to take it out for a spin grew ever greater. What initially began as an exciting jaunt actually netted plenty of useful knowledge for the rover’s further development.

Continue reading “A 4G Rover And The Benefits Of A Shakedown Mission” →

Building A Robot Rover For Those Tough Indoor Missions

August 30, 2019 by Maya Posch 4 Comments

Making an outdoor rover is easy stuff, with lots of folk having them doing their roving activities on beaches and alien worlds. Clearly the new frontier is indoor environments, a frontier which is helpfully being conquered by [Andreas Hoelldorfer]’s Mantis Rover.

OK, we’re kidding. This project started out life as a base for [Andreas]’s exquisite 3D printable robotic arm, but it’s even capable of carrying people around, as the embedded video after the break makes abundantly clear. The most eye-catching feature of the Mantis Rover are its Mecanum wheels, which allow it to move in any direction, and is perfect for those tight spots where getting stuck would be really awkward.

The Mecanum wheels are 3D printed, making the motors and the associated controllers the more complicated part of this package. Plans for the wheels involve casting some kind of rubber, to make the wheels more gentle on the floors it has to drive on. The electronics include TMC 5160 motor drivers and an STM32F407VET6 MCU, as well as a W5500-equipped custom ‘Robot Shield’.

It seems that there are still a lot of tweaks underway to make the project even more interesting. Maybe it’s the perfect foundation for your next indoor roving sessions at the office or local hackerspace?

Continue reading “Building A Robot Rover For Those Tough Indoor Missions” →

3D Printed Rover Enjoys Long Walks On The Beach

August 27, 2019 by Tom Nardi 13 Comments

More than a few hackers have put in the considerable time and effort required to build a rover inspired by NASA’s robotic Martian explorers, but unfortunately even the most well funded home tinkerer can’t afford the ticket to send their creation offworld. So most of these builds don’t journey through anything more exciting than a backyard sandbox. Not that we can blame their creators, we think a homebrew rover will look just as cool in your living room as it would traipsing through a rock quarry.

But the DIY rover status quo clearly wasn’t sufficient for [Jakob Krantz], who decided the best way to test his new Curiosity-inspired rover was to let it frolic around on the beach for an afternoon. But judging by the video after the break, his beefy 3D printed bot proved to be more than up to the task; powering through wildly uneven terrain with little difficulty.

Beyond a few “real” bearings here and there, all of the key components for the rover are 3D printed. [Jakob] did borrow a couple existing designs, like a printable bearing he found on Thingiverse, but for the most part he’s been toiling away at the design in Fusion 360 and using images of the real Curiosity rover as his guide.

Right now, he’s controlling the rover with a standard 6 channel RC receiver. Four channels are mapped to the steering servos, and a fifth to the single electronic speed control that commands the six wheel motors. But he’s recently added an Arduino to the rover which will eventually be in charge of interpreting the RC commands. This will allow more complex maneuvers with fewer channels, such as the ability to rotate in place.

We’re proud to count our very own [Roger Cheng] among the rover wrangling hackers of the world. An entire community has sprung up around his six-wheeled Sawppy, and the knowledge gained during its design and construction could be applicable to any number of other projects.

Continue reading “3D Printed Rover Enjoys Long Walks On The Beach” →

Life At JPL Hack Chat

August 19, 2019 by Dan Maloney 6 Comments

Join us on Wednesday, August 21st at noon Pacific for the Life at JPL Hack Chat with Arko!

There’s a reason why people use “rocket science” as a metaphor for things that are hard to do. Getting stuff from here to there when there is a billion miles away and across a hostile environment of freezing cold, searing heat, and pelting radiation isn’t something that’s easily accomplished. It takes a dedicated team of scientists and engineers working on machines that can reach out into the vastness of space and work flawlessly the whole time, and as much practice and testing as an Earth-based simulation can provide.

Arko, also known as Ara Kourchians, is a Robotics Electrical Engineer at the Jet Propulsion Laboratory, one of NASA’s research and development centers. Nestled at the outskirts of Pasadena against the flanks of the San Gabriel Mountains, JPL is the birthplace of the nation’s first satellite as well as the first successful interplanetary probe. They build the robots that explore the solar system and beyond for us; Arko gets to work on those space robots every day, and that might just be the coolest job in the world.

Join us on the Hack Chat to get your chance to ask all those burning questions you have about working at JPL. What’s it like to build hardware that will leave this world and travel to another? Get the inside story on how NASA designs and tests systems for space travel. And perhaps get a glimpse at what being a rocket scientist is all about.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 21 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.