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61 Articles

Long Live Jibo, Our Adorable Robot Companion

October 17, 2019 by 10 Comments

Jibo, the adorable robot made by Jibo, Inc., was getting phased out, but that didn’t stop [Guilherme Martins] from using his robot companion for one last hack.

When he found out that the company would be terminating production of new Jibos and shutting down their servers, he wanted to replace the brain of the robot so that it would continue to live on even after all of its software had become deprecated. By the time the project started, the SDK downloads had already been removed the from developer’s site, so they looked at other options for controlling Jibo.

The first challenge was to not break the form factor in order to disassemble Jibo. They only managed to remove the battery from the bottom, realizing that the glass frame held the brain room. From within the robot, they were able to find the endless rotation joint for the head and the heart of the electronics. Jibo uses a DC motor, encoder, and IR sensor at each of three distinct levels to detect reference points.

They decided to use Phidgets modules to interface with these devices. While the DC motor controller handles 2A and has an encoder port, the Phidgets are able to provide software with the encoder and PID built-in. The 4x Digital Input Module was used for detecting the IR switch and connecting the modules to the computer.

[Martins] decided to use LattePanda, a hackable Windows 10 development board, for the brain of the new Jibo. The board was luckily able to fit inside the compartment for Jibo, but since it requires more power the unit is powered with 12V regulated to 5V in order to have less current passing through the wires. The DC motors, meanwhile, run at 12V and the IR switches and encoders at 5V.

A program developed in Unity3D plays the eye animations, and a C# program interfaces with the Phidgets. The final configuration was to fit Jibo onto a robotic arm to augment its behaviors. We previously wrote about Toppi, the robotic arm artist, that was used as the base for Jibo’s new home.

You can check out the result in the video below.

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Hackaday Podcast 030: Seven Years Of RTL-SDR, 3D Printing Optimized For The Eye, Sega Audiophile, Swimming In Brighteners

August 9, 2019 by 3 Comments

Hackaday Editors Mike Szczys and Elliot Williams curate the awesome hacks from the past week. On this episode, we marvel about the legacy RTL-SDR has had on the software-defined radio scene, turn a critical ear to 16-bit console audio hardware, watch generative algorithms make 3D prints beautiful, and discover why printer paper is so very, very bright white.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Direct download (58 MB)

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Ping-Pong Ball Makes Great PID Example

July 31, 2019 by 11 Comments

It is a common situation in electronics to have a control loop, that is some sort of feedback that drives the input to a system such as a motor or a heater based upon a sensor to measure something like position or temperature. You’ll have a set point — whatever you want the sensor to read — and your job is to adjust the driving thing to make the sensor read the set point value. This seems easy, right? It does seem that way, but in realitythere’s a lot of nuance to doing it well and that usually involves at least some part of a PID (proportional, integral, derivative) controller. You can bog down in math trying to understand the PID but [Electronoobs] recent video shows a very simple test setup that clearly demonstrates what’s going on with an Arduino, a motor, a distance sensor, and a ping-pong ball. You can see the video below.

Imagine for a moment heating a tank of water as an example. The simple approach would be to turn on the heater and when the water reaches the setpoint, turn the heater off. The problem there is though that you will probably overshoot the target. The proportional part of a PID controller will only turn the heater fully on when the water is way under the target temperature. As the water gets closer to the right temperature, the controller will turn down the input — in this case using PWM. The closer the sensor reads to the setpoint, the lower the system will turn the heater.

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This Two-Wheeled RC Car Is Rather Quick

May 16, 2019 by 12 Comments

Radio control cars have always been fun, it’s true. With that said, it’s hard to deny that true speed was unlocked when lithium polymer batteries and brushless motors came to the fore. [Gear Down For What?] built himself a speedy RC car of his own design, and it’s only got two wheels to boot (Youtube link, embedded below).

The design is of the self-balancing type – if you’re thinking of an angry unmanned Segway with a point to prove, you’re in the ballpark. The brains of the machine come thanks to a Teensy 3.6, which runs the PID loops for balancing and control. An MPU6050 gyroscope & accelerometer provide the necessary sensing to enable the ‘bot to keep itself upright in varied conditions. Performance is impressive, with the car reaching speeds in excess of 40 MPH and managing to handle simple ramps and bumps with ease. It’s all wrapped up in a 3D printed frame which held up surprisingly well to many crashes into tripods and tarmac.

Such builds are not just fun; they’re an excellent way to learn useful control skills that can serve you well in industry and your own projects. You can pick up the finer details of control systems in a university engineering course, or you could give our primer a whirl. When you’ve whipped up your first awesome project, we’d love to hear about it. Video after the break.

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High-Style Ball Balancing Platform

February 2, 2019 by 14 Comments

If IKEA made ball-balancing PID robots, they’d probably look like this one.

This [Johan Link] build isn’t just about style. A look under the hood reveals not the standard, off-the-shelf microcontroller development board you might expect. Instead, [Johan] designed and built his own board with an ATmega32 to run the three servos that control the platform. The entire apparatus is made from a dozen or so 3D-printed parts that interlock to form the base, the platform, and the housing for the USB webcam that’s perched on an aluminum tube. From that vantage point, the camera’s images are analyzed with OpenCV and the center of the ball is located. A PID loop controls the three servos to center the ball on the platform, or razzle-dazzle it a little by moving the ball in a controlled circle. It’s quite a build, and the video below shows it in action.

We’ve seen a few balancing platforms before, but few with such style. This Stewart platform comes close, and this juggling platform gets extra points for closing the control loop with audio feedback. And for juggling, of course.

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Juggling Machine Listens To The Bounce To Keep Ball In The Air

July 25, 2018 by 10 Comments

It’s a seemingly simple task: bounce a ping-pong ball on a wooden paddle. So simple that almost anyone can pick up a ball and a paddle and make a reasonable job of it. Now, close your eyes and try to do it just by the sound the ball makes when it hits the paddle. That’s a little tougher, but this stepper-driven platform juggler manages it with aplomb.

That’s not to say that the path to the finished product in the video below was a smooth one for [tkuhn]. He went through multiple iterations over the last two years, including a version that surrounded the juggling platform with a fence of phototransistors to track where the ball was at any time. That drove four stepper motors through a cross-linkage that popped the platform up at just the right moment to keep the ball moving, and at just the right angle to nudge it back toward the center of the platform. The current version of the platform does away with the optical sensors in favor of four small microphones. The mics pick up the sharp, well-defined sound of the ball hitting the platform, process the signal through an analog circuit, and use that signal to trigger a flip-flop if the signal exceeds a setpoint. An Arduino then measures the time delay between arriving signals, calculates the ball’s position on the platform, and drives the steppers through a PID loop to issue the corrective bounce.

The video below is entrancing, but we found ourselves wishing for a side view of the action too. It’s an impressive build nonetheless, one that reminds us of the many maze-runner and Stewart platform robots we’ve seen.

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DIY Tube Oven Brings The Heat To Homebrew Semiconductor Fab

July 18, 2018 by 16 Comments

Specialized processes require specialized tools and instruments, and processes don’t get much more specialized than the making of semiconductors. There’s a huge industry devoted to making the equipment needed for semiconductor fabrication plants, but most of it is fabulously expensive and out of reach to the home gamer. Besides, where’s the fun in buying when you can build your own fab lab stuff, like this DIY tube oven?

A tube oven isn’t much more complicated than it sounds — it’s just a tube that gets hot. Really, really hot — [Nixie] is shooting for 1,200 °C. Not just any materials will do for such an oven, of course, and this one is built out of blocks of fused alumina ceramic. The cavity for the tube was machined with a hole saw and a homebrew jig that keeps everything aligned; at first we wondered why he didn’t use his lathe, but then we realized that chucking a brittle block of ceramic would probably not end well. A smaller hole saw was used to make trenches for the Kanthal heating element and the whole thing was put in a custom stainless enclosure. A second post covers the control electronics and test runs up to 1,000°C, which ends up looking a little like the Eye of Sauron.

We’ve been following [Nixie]’s home semiconductor fab buildout for a while now, starting with a sputtering rig for thin-film deposition. It’s been interesting to watch the progress, and we’re eager to see where this all leads.