Superbly Synchronized Servos Swaying Softly

September 18, 2019 by 4 Comments

LEDs and blinky projects are great, and will likely never fade from our favor. But would you look at this sweeping beauty? This mesmerizing display is made from 36 micro servos with partial Popsicle sticks pasted on the arms. After seeing a huge display with 450 servos at an art museum, [Doug Domke] was inspired to make a scaled-down version.

What [Doug] didn’t scale down is the delightful visuals that simple servo motion can produce. The code produces a three-minute looping show that gets progressively more awesome, and you can stare at that after the break. Behind the pegboard, a single, hardworking Arduino Uno controls three 16-channel PWM controllers that sweep the servos. We like to imagine things other than Popsicle sticks swirling around, like little paper pinwheels, or maybe optical illusion wheels for people with strong stomachs.

You won’t see these in the video, but there are five ultrasonic sensors mounted face-up on the back of the pegboard. [Doug] has optional code built in to allow the servo sticks to follow hand movement. We hope he’ll upload a demo of that feature soon.

Servos can be hypnotic as well as helpful, as we saw in this 114-servo word clock.

Continue reading “Superbly Synchronized Servos Swaying Softly” →

What’s In A Name? Tales Of Python, Perl, And The GIMP

September 18, 2019 by 58 Comments

In the older days of open source software, major projects tended to have their Benevolent Dictators For Life who made all the final decisions, and some mature projects still operate that way. Guido van Rossum famously called his language “Python” because he liked the British comics of the same name. That’s the sort of thing that only a single developer can get away with.

However, in these modern times of GitHub, GitLab, and other collaboration platforms, community-driven decision making has become a more and more common phenomenon, shifting software development towards democracy. People begin to think of themselves as “Python programmers” or “GIMP users” and the name of the project fuses irrevocably with their identity.

What happens when software projects fork, develop apart, or otherwise change significantly? Obviously, to prevent confusion, they get a new name, and all of those “Perl Monks” need to become “Raku Monks”.  Needless to say, what should be a trivial detail — what we’ve all decided to call this pile of ones and zeros or language constructs — can become a big deal. Don’t believe us? Here are the stories of renaming Python, Perl, and the GIMP.

Continue reading “What’s In A Name? Tales Of Python, Perl, And The GIMP” →

Arduino, Accelerometer, And TensorFlow Make You A Real-World Street Fighter

September 18, 2019 by 2 Comments

A question: if you’re controlling the classic video game Street Fighter with gestures, aren’t you just, you know, street fighting?

That’s a question [Charlie Gerard] is going to have to tackle should her AI gesture-recognition controller experiments take off. [Charlie] put together the game controller to learn more about the dark arts of machine learning in a fun and engaging way.

The controller consists of a battery-powered Arduino MKR1000 with WiFi and an MPU6050 accelerometer. Held in the hand, the controller streams accelerometer data to an external PC, capturing the characteristics of the motion. [Charlie] trained three different moves – a punch, an uppercut, and the dreaded Hadouken – and captured hundreds of examples of each. The raw data was massaged, converted to Tensors, and used to train a model for the three moves. Initial tests seem to work well. [Charlie] also made an online version that captures motion from your smartphone. The demo is explained in the video below; sadly, we couldn’t get more than three Hadoukens in before crashing it.

With most machine learning project seeming to concentrate on telling cats from dogs, this is a refreshing change. We’re seeing lots of offbeat machine learning projects these days, from cryptocurrency wallet attacks to a semi-creepy workout-monitoring gym camera.

Continue reading “Arduino, Accelerometer, And TensorFlow Make You A Real-World Street Fighter” →

Pizza Oven Build Exercises Forgotten Gym Ball

September 18, 2019 by 6 Comments

See, this is what happens when pizza lovers follow their dreams. It probably started innocently enough for [phammy57]—he got a pizza stone, then maybe one of those big rocking pizza cutters. Maybe he even learned how to toss the dough high in the air. But every time [phammy57] slid one of those homemade pies into the electric oven, the nagging feeling grew a little stronger. Eventually, he gave in to making pizza the way it’s supposed to be made, and built a wood-fired oven.

The most intriguing thing about this build is also the most important: this pizza preparer pivots on a gym ball, which served as the base for forming the oven. To do this, [phammy57] pushed the ball halfway through a hole in a big piece of plywood, effectively creating the world’s largest Pogo Bal (remember those?). Then he applied plastic wrap to the ball as a mold release, and laid down a thick mixture of vermiculite, cement, and water.

[phammy57] built the base from lightweight blocks, sculpting a nice arch for the top of the wood storage area. Once the dome was fastened to the base with the opening cut and outlined with brick, he cut a vent hole and built the chimney. Finally, it was time to add insulating blanket material, chicken wire, more vermiculite, and coat of plaster to finish. Take a brief look inside after the break.

It’s a long process of building, curing, and burning in, but the end result looks fantastic. We bet it pizzas like a champ, too. Probably gives this 45-second pizza oven a run for its money.

[Ed Note: If you’re still having trouble parsing the title, try it out with “build” as a noun and “exercises” as a verb.]

Continue reading “Pizza Oven Build Exercises Forgotten Gym Ball” →

Keeping Clocks On Time, The Swiss Way

September 17, 2019 by 31 Comments

Could there be a worse fate for a guy with a Swiss accent than to be subjected to a clock that’s seconds or even – horrors! – minutes off the correct time? Indeed not, which is why [The Guy With the Swiss Accent] went to great lengths to keep his IKEA radio-controlled clock on track.

For those who haven’t seen any of [Andreas Spiess]’ YouTube videos, you’ll know that he pokes a bit of fun at Swiss stereotypes such as precision and punctuality. But really, having a clock that’s supposed to synchronize to one of the many longwave radio atomic clocks sprinkled around the globe and yet fails to do so is irksome to even the least chrono-obsessive personality. His IKEA clock is supposed to read signals from station DCF77 in Germany, but even the sensitive receivers in such clocks can be defeated by subterranean locales such as [Andreas]’ shop. His solution was to provide a local version of DCF77 using a Raspberry Pi and code that sends modulated time signals to a GPIO pin. The pin is connected to a ferrite rod antenna, which of course means that the Pi is being turned into a radio transmitter and hence is probably violating the law. But as [Andreas] points out, if the power is kept low enough, the emissions will only ever be received by nearby clocks.

With his clock now safely synced to an NTP server via the tiny radio station, [Andreas] can get back to work on his other projects, such as work-hardening copper wire for antennas with a Harley, or a nuclear apocalypse-Tweeting Geiger counter.

Continue reading “Keeping Clocks On Time, The Swiss Way” →

Your Next Robot Needs Googly Eyes, And Other Lessons From Disney

September 17, 2019 by 11 Comments

There are so many important design decisions behind a robot: battery, means of locomotion, and position sensing, to name a few. But at a library in Helsinki, one of the most surprising design features for a librarian’s assistant robot was googly eyes. A company called Futurice built a robot for the Oodi library and found that googly eyes were a very important component.

The eyes are not to help the robot see, because of course they aren’t functional — at least not in that way. However without the eyes, robot designers found that people had trouble relating to the service robot. In addition, the robot needed emotions that it could show using the eyes and various sounds along with motion. This was inspired, apparently, by Disney’s rules for animation. In particular, the eyes would fit the rule of “exaggeration.” The robot could look bored when it had no task, excited when it was helping people, and unhappy when people were not being cooperative.

Continue reading “Your Next Robot Needs Googly Eyes, And Other Lessons From Disney” →

Glitching LED Display Proves Crowd Favorite

September 17, 2019 by 9 Comments

There’s something enchanting about the soft glow of a properly diffused LED, and this is only improved by greater numbers of LEDs. [Manoj Nathwani] was well aware of this, setting out to build a large display using ping-pong balls for their desirable optical qualities.Unfortunately, not everything went to plan, but sometimes that’s not all bad.

The matrix, built back in 2016 for EMF Camp, was sized at 32×18 elements, for a total of 576 pixels. This was achieved with the use of 12 WS2811 LED strips, with the lights set out on a 50mm grid. Cheap knock-off pingpong balls were used for their low cost, and they proved to be excellent diffusers for the LEDs.

With everything wired up to a NodeMCU, basic testing showed the system to be functioning well. However, once the full matrix was assembled in the field, things started to fall over. Basic commands would work for the first 200 LEDs or so, and then the entire matrix would begin to glitch out and display random colors. Unable to fix the problem in the field, [Manoj] elected to simply run the display as-is. Despite the problems, passers-by found the random animations to be rather beautiful anyway, particularly at night.

After the event, [Manoj] determined the issue was due to the excessive length of the data line, which in the final build was 48 meters long. While the problem may be rectified when [Manoj] revisits the project, the audience seemed to appreciate the first revision anyway.

LED displays will be a hacker staple until the heat death of the universe. Ping pong balls will also likely retain their position as a favorite diffuser. If you’ve got a great LED build of your very own, be sure to hit up the tips line!