Monthly Archives: October 2017

Students invent a low-cost electric wheelchair kit with Arduino

via Arduino Blog

While electric wheelchairs are a vital tool for those with restricted mobility, they typically cost around $2,500, an amount that’s not the most affordable. To address this problem, a group of students from Aviv High School in Israel have come up with a low-cost, 3D-printed motor conversion kit that connects to a standard push-chair without any permanent modification or damage.

The system uses a pair of motors to steer like a tank, and features a joystick and Arduino Uno for control. Another interesting feature is shown later in the video below, when it’s folded up for storage with the motor kit still attached.

You can check out the team’s website for more details this incredible project, as well as All3DP’s recent article here.

When Open Source Goes Closed

via SparkFun Electronics Blog Posts

I remember back at the… second (?) Open Source Hardware Summit, where Bre Pettis tried to explain (justify?) that the MakerBot Replicator 2 would not be an open design. I honestly don’t remember much of what was said, but I remember the mood in the room – it was dead quiet. It was as if this was the guy that single-handedly sold out the open source community. But this isn’t the story of MakerBot, or even to comment on whether or not what happened with them was right or wrong. If you want to catch up on those guys, check their wiki page. It reads a bit like a corporate monkey knife fight.

alt text

Photo courtesy of Flickr

The bigger question is whether or not there even is a “right” path. Can an open project go closed at any point? For that matter, why would the project owners want to go closed? And why start with open hardware in the first place?

For the vast majority of the people likely to read this, open source is a great thing. Open communication, transparency and a free exchange of design information helps us to create. It speeds up the process and makes for better designs. More than that, open source licenses help to protect the little guys from big companies trying to retroactively assert a patent on top of their previously open work. But as important, it gives us a sense of community, a connection to something greater than ourselves.

But let’s examine that more closely. In the end, every last company is in business to make money. How do you do that? You sell stuff, either goods or services. And as companies grow, the natural trajectory is to become bigger, move more product and take in even more money. How do you do that more effectively? You try to exert more control over your market, either by convincing potential customers that your products are better than anyone else’s, or by making it impossible for them to get products like yours anywhere else. I would submit that the former is healthy competition that benefits customers at large, and I believe open hardware fosters this. I would also submit that the latter isn’t based on the needs of the consumer at all, rather the needs (or wants) of the company.

alt text

Hey, it’s The Bobs.

I don’t mean to say that non-open companies are evil. There are plenty of examples of markets where designs are closed and there is tons of relatively “fair” competition, but the companies of interest just don’t share design info. They make their employees sign noncompete agreements and such, and we don’t really spend a lot of time criticizing them, because why bother? They most likely started off as a closed endeavor, so whatever. If I need a new toaster, I’m not going to go the distance to find one that’s an open design. Does that make me a fair-weather altruist? Maybe, but you gotta pick your battles, and the average person only has so many hours in the day…

This becomes far more complicated the deeper we go, and my thinking diverges in several directions at this point. Is it wrong for a previously open company to go closed? If a large company approached me with a big offer to buy me out of my little open company, would I be able to say no? Financial independence is very attractive, and it would allow me the ability to work on whatever I wanted without any hindrances, spend as much time with my family as I wanted, etc. Being altruistic is easier when you don’t have dependents, less so when you do (and by “dependents” I don’t mean just real, flesh-and-blood children. All of my projects and interests are “children” demanding attention).

For that matter, what does success look like for an open source company? Is it financial success? Is it getting bought out by Google? And if you’re an open company, what would you offer a potential purchaser for their money? It isn’t intellectual property, I can tell you that. You can give them access to the community that’s grown around your open company, you give them the brand name, you give them physical assets (parts stock, machines, etc)… but without IP, it’s a much bigger gamble for them. So do you create IP? As we’ve seen, the open source community can turn on you remarkably quickly for a move like that, and I know of at least one company in our little community that’s struggling with that possibility right now.

alt text

Photo courtesy of DIOA

As with most of the topics I write on, I’m sure I’m grossly oversimplifying the issue. But here’s my take (you’re under no obligation to agree): once open, always open, if for no other reason than your audience will continue to demand it and you need them to survive. But open source pursuits have difficulty with increasing revenues and increasing audience size - it’s not impossible, but it seems to be more difficult to be huge and attentive to your community. And at some point those two things need to find some kind of equilibrium. Where does that equilibrium occur? I have no idea. In this bizarre utopian image of the future that I maintain, I imagine companies like ours being more like regional entities with smaller audiences so that we can better serve and contribute meaningfully to the open source community, free of the ethical compromises that plague larger entities, and free to be creative with less concern for the bottom line.

And everybody gets a pony and a big chocolate cake.

comments | comment feed

Twitter makers love Halloween

via Raspberry Pi

Halloween is almost upon us! In honour of one of the maker community’s favourite howlidays, here are some posts from enthusiastic makers on Twitter to get you inspired and prepared for the big event.

Lorraine’s VR Puppet

Lorraine Underwood on Twitter

Using a @Raspberry_Pi with @pimoroni tilt hat to make a cool puppet for #Halloween

Made with a Pimoroni Pan-Tilt HAT, a Raspberry Pi, and some VR software on her phone, Lorraine Underwood‘s puppet is going to be a rather fitting doorman to interact with this year’s trick-or-treaters. Follow her project’s progress as she posts it on her blog.

Firr’s Monster-Mashing House

Firr on Twitter

Making my house super spooky for Halloween!

Harnessing the one song guaranteed to earworm its way into my mind this October, Firr has upgraded his house to sing for all those daring enough to approach it this coming All Hallows’ Eve.

Firr used resources from Adafruit, along with three projectors, two Raspberry Pis, and some speakers, to create this semi-interactive display.

While the eyes can move on their own, a joystick can be added for direct control. Firr created a switch that goes between autonomous animation and direct control.

Find out more on the website.

Justin’s Snake Eyes Pumpkin

Justin Smith on Twitter

First #pumpkin of the season for Friday the 13th! @PaintYourDragon’s snake eyes bonnet for the #RaspberryPi to handle the eye animation.

The Animated Snake Eyes Bonnet is definitely one of the freakiest products to come from the Adafruit lab, and it’s the perfect upgrade for any carved pumpkin this Halloween. Attach the bonnet to a Raspberry Pi 3, or the smaller Zero or Zero W, and thus add animated eyes to your scary orange masterpiece, as Justin Smith demonstrates in his video. The effect will terrify even the bravest of trick-or-treaters! Just make sure you don’t light a candle in there too…we’re not sure how fire-proof the tech is.

And then there’s this…

EmmArarrghhhhhh on Twitter

Squishy eye keyboard? Anyone? Made with @Raspberry_Pi @pimoroni’s Explorer HAT Pro and a pile of stuff from @Poundland 😂👀‼️

Yeah…the line between frightening and funny is never thinner than on Halloween.

Make and share this Halloween!

For more Halloween project ideas, check out our free resources including Scary ‘Spot the difference’ and the new Pioneers-inspired Pride and Prejudice‘ for zombies.

Halloween Pride and Prejudice Zombies Raspberry Pi

It is a truth universally acknowledged that a single man in possession of the zombie virus must be in want of braaaaaaains.

No matter whether you share your Halloween builds on Twitter, Facebook, G+, Instagram, or YouTube, we want to see them — make sure to tag us in your posts. We also have a comment section below this post, so go ahead and fill it with your ideas, links to completed projects, and general chat about the world of RasBOOrry Pi!

…sorry, that’s a hideous play on words. I apologise.

The post Twitter makers love Halloween appeared first on Raspberry Pi.

Free PCB Sunday: Pick your PCB

via Dangerous Prototypes


We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Be sure to use a real e-mail in the address field so we can contact you with the coupon.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.
  • PCBs are scrap and have no value, due to limited supply it is not possible to replace a board lost in the post

Be the first to comment, subscribe to the RSS feed.

App note: Grid-connected solar microinverter reference design

via Dangerous Prototypes


A good read from Microchip on the theory behind inverter design connected to grip power. Link here (PDF)

There are two main requirements for solar inverter systems: harvest available energy from the PV panel and inject a sinusoidal current into the grid in phase with the grid voltage. In order to harvest the energy out of the PV panel, a Maximum Power Point Tracking (MPPT) algorithm is required. This algorithm determines the maximum amount of power available from the PV module at any given time. Interfacing to the grid requires solar inverter systems to abide by certain standards given by utility companies. These standards, such as EN61000-3-2, IEEE1547 and the U.S. National Electrical Code (NEC) 690, deal with power quality, safety, grounding and detection of islanding conditions.

App note: On-grid solar microinverter on Freescale MC56F82xx/MC56F82xxx DSCs

via Dangerous Prototypes


Application note from Freescale Semiconductor about microinverter solution develop together with Future Electronics. Link here (PDF)

In recent years, demand for renewable energy has increased significantly. The development of devices utilizing clean energy such as solar, wind, geothermal, and fuel cells attracts more and more attention. Solar energy harvesting is developing fast and will play a more important role as a global energy source. One of the ways to capture solar energy is via photovoltaic power generation systems, which are connected to the grid through power inverters. Therefore, many companies are focusing on development of photovoltaic grid-tie inverters. Freescale offers digital signal controllers, the MC56F8xxx family, that are well suited to ongrid solar inverter designs.