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Hackaday Links: September 6, 2015

September 6, 2015 by 10 Comments

The MeArm is a cool little robot arm that can be controlled with just about any microcontroller. There’s a new version of it up on Thingiverse.

Here’s something to get kids interested in robotics: the GoBox is a robot kit with multiple ‘missions’ delivered monthly. The robot is based on the Raspberry Pi and Scratch – the Apple II and BASIC of today, I guess.

What happens when a popular electronics YouTuber completely debunks a product? Hundreds of dislikes appear on the YouTube videos he made. Hundreds of dislikes from Vietnam appeared on [Dave Jones]’ videos debunking the Batterizer. In fact, more people from Vietnam disliked the video than viewed it. Yes, weird YouTube dislike farms like this exist, and if you can do it on the Internet, you can also pay people to do it on the Internet.

The ESP8266 is slowly becoming a board that’s as easy to use as an Arduino. Now there’s a board that turns it into an Arduino.

The Vintage Computer Festival Midwest was last week,  and [chris537a] shot a video of all the cool stuff. [vikram4819] put an album up on imgur. Yes, someone was selling a Sparcbook for $300. I’m holding out for a PowerPC ThinkPad, though…

Washington DC area hackers, don’t forget to RSVP for the Hackaday Meetup on Saturday. Bring a hack to show off and spend the evening socializing with the Hackaday community. Check out the announcement post for more info.

CubeSat Challenge Winners Show Interesting Design Approaches

September 6, 2015 by 12 Comments

The winners are in for the GrabCad CubeSat Challenge, which asked designers to rethink the way that CubeSats are built. These tiny 10 cm square satellites are the hot thing in orbit, and the competition was looking for new ways to build and pack more into this tiny space. The winners offered some fascinating new approaches to building CubeSats, and some excellent design lessons that anyone can use.

The winner was FoldSat, by [Paolo Minetola]. His excellent design is a 3D printed folding case for a satellite that is built from just two 3D printed parts. The case can be snapped together and offers multiple ways to mount electronic components and sensors inside. [Paolo] estimates that it could save 40% time and 30% materials from existing CubeSat casings, which means more space inside and more time to build. It is an excellent example of how 3D printing can make things cheaper, easier and better, all at the same time.

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It’s An Upright Piano, It’s A Looper, It’s A Pi Project

September 6, 2015 by 6 Comments

We don’t really get out much, but we have noticed that there are brightly painted upright pianos in public places these days. Research indicates that these pianos are being placed by small, independent local organizations, most of which aim to spread the joy of music and encourage a sense of community.

[Sean and Mike] took this idea a couple of steps further with Quaver, their analog looping piano. Both of them are maker/musicians based in Lancaster, Pennsylvania, which happens to be a hot spot for public pianos. [Sean and Mike] often stop to play them and wanted a good way to capture their impromptu masterpieces. Quaver is an antique upright that has been modified to record, save, loop, and upload music to the internet. It does all of this through a simple and intuitive user interface and a Raspi 2. Quaver works a lot like a 4-track recorder, so up to four people can potentially contribute to a song.

The player sits down, cracks their knuckles, and presses our personal favorite part of the interface: the giant, irresistible record button. A friendly scrolling LED matrix display tells them to start playing. Once they are satisfied, they press the button again to stop the recording, and the notes they played immediately play back in a loop through a pair of salvaged Bose speakers from the 1980s. This is just the beginning of the fun as you play along with your looping recording, building up several voices worth of song!

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Hams Talk Digital

September 6, 2015 by 45 Comments

Morse code qualifies as a digital mode, although organic brains are somewhat better at copying it than electronic ones. Ham radio operators that did “phone” (ham-talk for voice) started out with AM modulation. Sometime after World War II, there was widespread adoption of single side band or SSB. SSB takes up less bandwidth and is more reliable than AM modulation. On the digital side, hams turned to different and more sophisticated digital transmission types with computers pushing bandwidth down and reliability up. However, a recent trend has been to encode voice over ham radio–sort of VoIP with radio instead of Ethernet–using an open source program called freedv.

[AA6E] made a very informative video where he carries on a QSO (a conversation) with a distant station using freedv. What makes it interesting, is towards the end when the two stations switch to regular SSB. The difference is dramatic and really points out how even with less bandwidth (roughly 3 kHz for SSB vs 1.25 kHz), the digital mode is superior. The freedv software (available for Windows or Linux) compresses audio to 700-1600 bits per second and spreads it over 16 QPSK signals.

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Better Racing With Power Wheels

September 6, 2015 by 6 Comments

For the last few months, teams across the US have taken old Power Wheels and other electric vehicles meant for children and turned them into racing machines capable of flying around the track at speeds pf over 30 miles per hour. How do you take the plastic chassis of a kid’s toy and turn it into a Power Racer? [Dane] from team Chibi-Atomic-Thing tells us how.

In classic Power Racing Series fashion, this year’s build began with last year’s chassis. At the 2014 NYC Maker Faire, a weld on the steering linkages failed, necessitating some quick work to replace some bad welds. Poor fabrication wasn’t the only shortcoming of last year’s car; the rear axle was fixed, the brakes were terrible, and the gearbox wasn’t quite as good as it could be.

The team had a few months to make the necessary changes for this season’s races. Because they were adding advanced and arcane technology known as a differential this year, a second disc brake holster would need to be fabricated for the other rear wheel. A new motor controller was added, but the team is mum on why exactly they need an eight-speed gearbox when the longest straight on the track is about fifty feet.

The answer to why a tiny electric car needs more gears than a clock is for now, at least, unknown. Hopefully it will be revealed at the next Power Racing Series race at the NYC Maker Faire in a few weeks. Until then, check out the video of the 2015 Detroit race below.

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Hackaday Prize Semifinalist: Picking Up Litter With Robots

September 5, 2015 by 9 Comments

On beaches, in parks, and in [BDM]’s back yard, there’s a lot of liter everywhere. The normal solution to this problem is to hire someone or find some volunteers to pick up all this trash. We’re living in the future, though, and that means robots. For his Hackaday Prize entry, [BDM] is building a robot that picks up trash.

A robot that picks up litter is a very, very interesting problem. It can’t be controlled by a person, or else it would be more efficient to just get out there and kill your back picking up bottles. This means it must work autonomously, and that means identifying litter, picking it up, and disposing of it.

For the identification part of the problem, [BDM] is using computer vision that captures an RGB image and discriminates against natural objects. Right now the computer vision is far from perfect, but it does a very good job, all things considering.

The next biggest problem is picking the trash up and disposing of it. For this, [BDM] has repurposed a Power Wheels and attached a DIY robot arm. It’s not a very powerful arm, and a children’s toy probably isn’t the best platform, but it is the start of something very, very cool.

You can check out [BDM]’s video for the project below.

The 2015 Hackaday Prize is sponsored by:

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ESP8266 Web Server Farm

September 5, 2015 by 15 Comments

There seems to be a hacker maxim that whatever gadget you are working with, it would be better to have several of them running together. That might explain the ESP8266 web server farm that [Eldon Brown] has built. Yup, a web server farm made from three of everyone’s favorite WiFi dongle, the humble ESP8266.

Eldon’s server farm is currently serving web pages here, running on three ESP8266 boards. Or it was before this posting reduced it to a smoking ruin (screenshot below just in case). Each module is running a dynamic web page and some clever programming he came up with that makes transferring data over these cheap devices quicker.

His page isn’t anything too fancy but it is impressive considering it is running on about $30 worth of hardware, including the breadboard it is wired into. The page includes dynamically-generated graphics and some back-end stuff. I don’t think that it will replace any LAMP servers anytime soon (the ESP8266 took about 2.6 seconds to generate the page below), but it is an impressive hack. [Eldon] has made the full code of the web server that is running the pages available. So, lets add web server farm to the list of things that this neat little device can handle, next to plant weigher, Bitcoin price tracker, MP3 player and many more…

Thanks to [PuceBaboon] for the tip!

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