Print Chess Pieces, Then Defeat The Chess-Playing Printer

March 6, 2021 by Brian McEvoy 4 Comments

Chess is undoubtedly a game of the mind. Sadly, some of the nuances are lost when you play on a computer screen. When a game is tactile, it carries a different gravity. Look at a poker player shuffling chips, and you’ll see that when a physical object is on the line, you play for keeps. [Matou], who is no stranger to 3D printing, wanted that tactility, but he didn’t stop at 3D printed pieces. He made parts to transform his Creality Ender 3 Pro into a chess-playing robot.

To convert his printer, [Matou] designed a kit that fits over the print head to turn a hotend into a cool gripper. The extruder motor now pulls a string to close the claw, which is a darn clever way to repurpose the mechanism. A webcam watches the action, while machine vision determines what the player is doing, then queries a chess AI, and sends the next move to OctoPrint on a connected RasPi. If two people had similar setups, it should be no trouble to play tactile chess from opposite ends of the globe.

Physical chess pieces and computers have mixed for a while and probably claimed equal time for design and gameplay. There are a couple of approaches to automating movement from lifting like [Matou], or you can keep them in contact with the board and move them from below.

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OnShape To Robot Models Made Easier

February 28, 2021 by Al Williams 7 Comments

We live in a time where our phones have computing power that would have been the envy of NASA a few decades ago. So, in theory, we should be able to simulate just about anything. Thanks to [rhoban], robots you design in OnShape — a popular CAD tool — are now easier to simulate using several common simulation tools.

Electronic circuits are pretty easy to simulate, because we typically draw schematics and circuit simulators can capture those schematics readily. But simulating physics for robotic designs is a bit trickier. Gazebo and Pybullet both can use SDF files or URDF. However, building those files is often a separate process from actual physical design even though you probably did the design using a CAD tool. Even if you don’t use OnShape, you can probably import your preferred format and then bridge to the simulation file format without having to manually recreate your design. You can see the author walk through the process in the video below.

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These Micro Mice Have Macro Control

December 6, 2020 by Kerry Scharfglass 7 Comments

Few things fascinate a simple Hackaday writer as much as a tiny robot. We’ve been watching [Keri]’s utterly beguiling micromouse builds for a while now, but the fifth version of the KERISE series (machine translation) of ‘bots takes the design to new heights.

A family of mice v1 (largest) to v5 (smallest)

For context, micromouse is a competition where robots complete to solve mazes of varying pattern but standardized size by driving through them with no guidance or compute offboard of the robot itself. Historically the mazes were 3 meter squares composed of a 16 x 16 grid of cells, each 180mm on a side and 50mm tall, which puts bounds on the size of the robots involved.

What are the hallmarks of a [Keri] micromouse design? Well this is micromouse, so everything is pretty small. But [Keri]’s attention to detail in forming miniaturized mechanisms and 3D structures out of PCBs really stands out. They’ve been building micromouse robots since 2016, testing new design features with each iteration. Versions three and four had a wild suction fan to improve traction for faster maneuvering, but the KERISE v5 removes this to emphasize light weight and small size. The resulting vehicle is a shocking 30mm x 32mm! We’re following along through a translation to English, but we gather that [Keri] feels that there is still plenty of space on the main PCBA now that the fan is gone.

The processor is a now familiar ESP32-PICO-D4, though the wireless radios are unused so far. As far as environmental sensing is concerned the v5 has an impressive compliment given its micro size. For position sensing there are custom magnetic encoders and a 3 DOF IMU. And for sensing the maze there are four side-looking IR emitter/receiver pairs and one forward-looking VL6180X laser rangefinder for measurements out to 100 or 150mm. Most of these sensors are mounted on little PCB ‘blades’ which are double sided (check out how the PCB shields the IR emitter from it’s receiver!) and soldered into slots perpendicular to the PCBA that makes up the main chassis. It goes without saying that the rest of the frame is built up of custom 3D printed parts and gearboxes.

If you’d like to build a KERISE yourself, [Keri] has what looks to be complete mechanical, electrical, and firmware sources for v1, v2, and v3 on their Github. To see the KERISE v5 dance on a spinning sheet of paper, check out the video after the break. You don’t want to miss it!

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A Crust-Cutting, Carrot-Chopping Robot

November 30, 2020 by Kristina Panos 9 Comments

[3DprintedLife] sure does hate bread crust. Not the upper portion of homemade bread, mind you — just that nasty stuff around the edges of store-bought loaves. Several dozen hours of CAD later, [3DprintedLife] had themselves a crust-cutting robot that also chops vegetables.

This De-Cruster 9000 is essentially a 2-axis robotic guillotine over a turntable. It uses a Raspberry Pi 4 and OpenCV to seek and destroy bread crusts with a dull dollar store knife. Aside from the compact design, our favorite part has to be the firmware limit switches baked into the custom control board. The stepper drivers have this fancy feature called StallGuard™ that constantly reads the back EMF to determine the load the motor is under. If you have it flag you right before the motor hits the end of the rail and stalls, bam, you have a firmware limit switch. Watch it remove crusts and chop a lot of carrots with faces after the break.

This is far from the dangerous-looking robot we’ve seen lately. Remember this hair-cutting contraption?

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Hackaday Links: November 22, 2020

November 22, 2020 by Dan Maloney 6 Comments

Remember DSRC? If the initialism doesn’t ring a bell, don’t worry — Dedicated Short-Range Communications, a radio service intended to let cars in traffic talk to each other, never really caught on. Back in 1999, when the Federal Communications Commission set aside 75 MHz of spectrum in the 5.9-GHz band, it probably seemed like a good idea — after all, the flying cars of the future would surely need a way to communicate with each other. Only about 15,000 vehicles in the US have DSRC, and so the FCC decided to snatch back the whole 75-MHz slice and reallocate it. The lower 45 MHz will be tacked onto the existing unlicensed 5.8-GHz band where WiFi now lives, providing interesting opportunities in wireless networking. Fans of chatty cars need not fret, though — the upper 30 MHz block is being reallocated to a different Intelligent Transportation System Service called C-V2X, for Cellular Vehicle to Everything, which by its name alone is far cooler and therefore more likely to succeed.

NASA keeps dropping cool teasers of the Mars 2020 mission as the package containing the Perseverance rover hurtles across space on its way to a February rendezvous with the Red Planet. The latest: you can listen to the faint sounds the rover is making as it gets ready for its date with destiny. While we’ve heard sounds from Mars before — the InSight lander used its seismometer to record the Martian wind — Perseverance is the first Mars rover equipped with actual microphones. It’s pretty neat to hear the faint whirring of the rover’s thermal management system pump doing its thing in interplanetary space, and even cooler to think that we’ll soon hear what it sounds like to land on Mars.

Speaking of space, back at the beginning of 2020 — you know, a couple of million years ago — we kicked off the Hack Chat series by talking with Alberto Caballero about his “Habitable Exoplanets” project, a crowd-sourced search for “Earth 2.0”. We found it fascinating that amateur astronomers using off-the-shelf gear could detect the subtle signs of planets orbiting stars half a galaxy away. We’ve kept in touch with Alberto since then, and he recently tipped us off to his new SETI Project. Following the citizen-science model of the Habitable Exoplanets project, Alberto is looking to recruit amateur radio astronomers willing to turn their antennas in the direction of stars similar to the Sun, where it just might be possible for intelligent life to have formed. Check out the PDF summary of the project which includes the modest technical requirements for getting in on the SETI action.

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Really Useful Robot

November 12, 2020 by Bryan Cockfield 8 Comments

[James Bruton] is an impressive roboticist, building all kinds of robots from tracked, exploring robots to Boston Dynamics-esque legged robots. However, many of the robots are proof-of-concept builds that explore machine learning, computer vision, or unique movements and characteristics. This latest build make use of everything he’s learned from building those but strives to be useful on a day-to-day basis as well, and is part of the beginning of a series he is doing on building a Really Useful Robot. (Video, embedded below.)

While the robot isn’t quite finished yet, his first video in this series explores the idea behind the build and the construction of the base of the robot itself. He wants this robot to be able to navigate its environment but also carry out instructions such as retrieving a small object from a table. For that it needs a heavy base which is built from large 3D-printed panels with two brushless motors with encoders for driving the custom wheels, along with a suspension built from casters and a special hinge. Also included in the base is an Nvidia Jetson for running the robot, and also handling some heavy lifting tasks such as image recognition.

As of this writing, [James] has also released his second video in the series which goes into detail about the mapping and navigation functions of the robots, and we’re excited to see the finished product. Of course, if you want to see some of [James]’s other projects be sure to check out his tracked rover or his investigations into legged robots.

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Walmart Gives Up On Stock-Checking Robots

November 6, 2020 by Al Williams 37 Comments

We’ve seen the Jetsons, Star Wars, and Silent Running. In the future, all the menial jobs will be done by robots. But Walmart is reversing plans to have six-foot-tall robots scan store shelves to check stock levels. The robots, from a company called Bossa Nova Robotics, apparently worked well enough and Walmart had promoted the idea in many investor-related events, promising that robot workers would reduce labor costs while better stock levels would increase sales.

So why did the retail giant say no to these ‘droids? Apparently, they found better ways to check stock and, according to a quote in the Wall Street Journal’s article about the decision, shoppers reacted negatively to sharing the aisle with the roving machines.

The robots didn’t just check stock. They could also check prices and find misplaced items. You can see a promotional video about the device below. Continue reading “Walmart Gives Up On Stock-Checking Robots” →