Category Archives: Aggregated

#FreePCB via Twitter to 2 random RTs

via Dangerous Prototypes

BP-600x373

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

Using “Ultracapacitors” as a power conditioner and ballast for transient high-power loads (or “How to run your HF rig from D-cells” – sort of…)

via Dangerous Prototypes

cap_ballast_bank_2a

KA7OEI writes:

An advantage of Lead-Acid, NiCd, Lithium Ion and some NiMH cell types is that they have quite low internal resistance compared Alkaline cells: Even an aging lead acid battery that is near the end of its useful life may seem to be “OK” based on a load test as its internal resistance can remain comparatively low even though it may have lost most of its storage capacity!
One could ask, then, why now simply parallel Alkaline cells, with their ready availability, long life and high storage capacity with one of these other cell types and get the best of both worlds? In theory you could – if you had some sort of charge control circuitry that was capable of efficiently meting out the energy from the alkaline pack and using it to supplement the “other” storage medium (e.g. lead-acid, lithium-ion, etc.) but you cannot simply connect the two types in parallel and expect to efficiently utilize the available power capacity of both types of storage cell – this, due to the wildly different voltage and charge requirements.
Even if you do use a fairly small-ish (e.g. 7-10 amp-hour) lead-acid or lithium-ion battery pack, even though its internal resistance may be low compared to that of alkaline packs, it likely cannot source the 15-20 amp current peaks of, say, a 100 watt SSB transceiver without excess voltage drop, particularly if it isn’t brand new.

This is where the use of “Ultracapacitors” come in.

Details at KA7OEI’s blog.

Bus Pirate v3.8 free PCB build

via Dangerous Prototypes

finished-large-600

Ilias Giechaskiel blogged about his free Bus Pirate v3.8 PCB build.  The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff.

The next step was to burn the bootloader onto the Bus Pirate. Though I have found a couple of good resources for this already (1 and 2), I needed to modify a few steps as I was running Linux (also, the second link is in Spanish, so repeating some of what it says in English is probably a good thing). Though I already owned a PICkit 3, I hadn’t yet used it, as I tend to work with Atmel chips, so I first had to install the toolchain.

If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

HOW TO: Shenzhen Spring Festival/Chinese New Year

via Dangerous Prototypes

aeon2

By 2016 most hackers have some idea that China shuts down for a month every year. If not, learn it: from some time in January to some time in February the world’s largest country and manufacturing capital, one of the biggest economies, closes shop. Nothing is made or shipped.

While the whole country celebrates, Shenzhen is uniquely populated entirely by migrant workers from the north who leave for Spring Festival. All the teenagers who live in dorms and build your iPhone make a once yearly trek to see their families. The mass exodus from Shenzhen to northern China is billed as the worlds largest human migration. Its documented in “The Last Train Home”.

luggage-dragger-1

It starts slowly at first. You see a few people dragging luggage down the street, then a few more. Suddenly they’re everywhere.

Continue below for fireworks, gambling, the great migration, and how to deal with suppliers during Chinese New Year.

luggage-draggers

Everyone has a bag of water, food, and snacks. This is what they’ll subsist on until they reach their hometown in a few days.

smuggle-shop

Here a young couple stops at shop that sells baby formula, food, and shampoo smuggled from Hong Kong. Anything from here makes an impressive gift back home. Just to the left, out of frame, there’s a woman fighting with a restaurant owner. She says the food made her husband sick and she wants 100RMB ($16USD), likely a New Years scam for a few dollars to get back home.

bus

Random charter buses show up on every street. And then it goes silent.

luggage

For three solid weeks the infrastructure that supports 12-15 million people simply ceases to exist. First the factory labor goes: catching early buses and trains, some for 3-5days of travel. Without factories the couriers don’t have work, so all but the biggest delivery service stops working.

There’s no buyers or sellers in the market, so our local late night BBQ place is empty and closes for two weeks. All the hardware stores, salons, stationary shops, everything, completely closed. Its a ghost town out there, McDonald’s is about the only thing open.

If you work with China you need to take Spring Festival seriously. Rushing a last minute order or production before Spring Festival is just incomprehensibly stupid. Yet every year people desperately flail about trying to get something done a week or two or three before the holiday, even people who should know better.

Worse, there’s always a couple who offer to DO ANYTHING OR PAY ANYTHING!!! Yeah, anything except properly plan your production. Even a month ahead of the holiday nobody wants to take on new jobs. Offering to PAY ANYTHING!!! is incredibly insulting to suppliers, they value relationships and cooperation (and the once-a-year chance to see their family).

A half billion workers will ride filthy, feted, crowded, stinking trains for 5 days to visit some hellish frozen northern Chinese coal-burning village where families nag them to make more money, get married, and pop out a baby. Yeah, they don’t care about your damn Kickstart deadline.

Smart people know: the last order before Spring Festival is taken October 10th, after China National Day.

fireworks-shenzhen

So what to do in an empty Chinese mega city? Fireworks, while technically not permitted in Shenzhen, are everywhere. Kids and teenagers sell fireworks in the food streets from Styrofoam coolers.

They’ve got the good stuff. Snap-pops and sparklers at the low end. Rolls of 780,000 firecrackers and 38 shot mortars at the high end. There’s even a concierge lighting service.

safety-glasses

Wear safety glasses and ear plugs. Even the humble snap-pops are 10 to 20 times more powerful than those in America, they can easily make your ears ring for a few minutes if you empty a few thousand into a condom and throw it on the street.

heheihoi4

Locals play a game call Fish, Shrimp, Crab. Bet 5RMB ($0.80USD) or more on the fish, shrimp, crab, gourd, coin or cock. A dealer shakes three dice with these same symbols. If your symbol comes up you win 2x, 3x, or 4x your bet.

Betting is frowned upon so tables fold up quickly during regular police patrols, but it generally seems to be tolerated. We never gamble, because math, but “he hei hoi” is an interesting local cultural experience that goes well with beer and fireworks.

Spring Festival. Think of it as Christmas and New Years all rolled into one, then stretched out for a month. There’s kitschy decorations and annoying repetitive holiday muzak. There’s annual traditions involving food, alcohol, and vice. There’s visiting family you don’t like in far away places you’d rather not be. And never, under any circumstances, does anything get done before or during the holiday.

Another new Raspbian release

via Raspberry Pi

Some of you may have spotted that there is a new Raspbian release available for download. For most people, this is primarily updates and bug fixes to the existing Jessie image – but there’s one exciting new feature that might be of interest to some people…

But before we get to that, here’s a summary of the other changes.

New versions of applications

There are new versions of many of the standard applications.

Sonic Pi is now at version 2.9. A full list of changes can be found in the History section of the Info window in Sonic Pi, but the highlights include two new effects functions, a new logging system, and the inclusion of all of Sam Aaron’s articles for The Magpi magazine as part of the online tutorials.

Scratch is now at version 20160115. This has improved sound input capabilities, support for the CamJam EduKit 3 robotics board, basic PWM support in the GPIO server, and various improvements to the display, including font scaling.

Mathematica is now at version 10.3. This adds support for a larger set of the functionality detailed in Stephen Wolfram’s new “Elementary Introduction to the Wolfram Language” book. It also supports the use of the Sense HAT, adds interfacing to Arduino, and includes many new Mathematica functions.

Node-RED is now at version 12.5 – this adds no significant new functionality, but fixes a number of bugs and contains some internal performance improvements.

New versions of libraries

WiringPi has been updated to version 2.31, which allows GPIO pins to be accessed from applications that use the library without needing to use sudo. For more details, see the WiringPi website.

The RPi.GPIO Python library has been updated to version 0.6.1 which includes some bug fixes which affected the new GPIO Zero library.

The Java platform included has been updated to version 8, update 65.

Bug fixes

The volume/audio device icon on the taskbar is now compatible with a wider range of USB audio devices – people reported that it was impossible to set some USB sound devices as the default output. Due to the way the ALSA system works, it is very difficult to make this completely infallible, but the new version should work with a much wider selection of devices than before.

The Main Menu editor now allows new menus to be created. In earlier versions, due to an issue with the way the LXDE desktop environment interpreted its configuration files, creating a new menu caused all other menus to be hidden – this should now work correctly.

The GUI Raspberry Pi Configuration and command-line raspi-config applications now offer the correct overclocking options on all Pi 1, Pi 2 and Pi Zero boards. There are also some updated language translations submitted by the community – many thanks to the translators!

The Wastebasket is now consistently named as such everywhere when the desktop is set to British English. (It previously had a wide selection of names in different places, including Trash and Rubbish Bin…)

The ping command no longer requires sudo.

One more thing…

We hope the above changes are useful, but Raspbian will still look pretty much the same as it did for the last release in November. But we have been working on one other thing behind the scenes for this release: this won’t be of interest to most users, but for some, we hope it will be very useful.

In this release we are shipping an experimental OpenGL driver for the desktop which uses the GPU to provide hardware acceleration. This is turned off by default – if you want to enable it, you can find it in the command-line version of raspi-config, under Advanced Options->GL Driver. Due to memory requirements, this will not work on Pi 1 or Pi Zero boards – it is solely for Pi 2. (raspi-config will only allow it to be enabled on a Pi 2; be warned that if you enable it on a Pi 2 and then move that SD card into a Pi 1 or Pi Zero, the Pi will not boot.)

If you don’t use this option, the desktop does have OpenGL support, but it uses a very slow software renderer, which makes all but the most basic OpenGL applications pretty much unusable. The hardware-accelerated version is much faster, and makes some quite decent OpenGL games playable on the Pi.

As a quick demonstration of the effect of the driver, try installing the mesa-utils package with

sudo apt-get install mesa-utils

This installs a simple OpenGL demo program called glxgears which shows three rotating gear-wheels. To run it, type

glxgears

With the standard software renderer, this runs at around 23 frames per second, flickers a lot, and doesn’t actually show the correct colours. If you try it again with the new driver enabled, it runs at the screen refresh rate of 60 fps, with no flicker and the correct colours.

Rotating gears are all very well, but they aren’t that exciting, are they? So how about some actual games? One that is popular in the office is Neverball – try

sudo apt-get install neverball

This barely runs at all under the software renderer, but is quite slick and playable with the new driver.

neverball

Or try Oolite, which looks quite similar to another game that those of us of a certain age remember fondly.

sudo apt-get install oolite

oolite

There are various other OpenGL games and applications available in apt – to find them, try

apt-cache search opengl

Bear in mind that this is an experimental release of the driver which we are making available to the community as a public beta test; it is still slightly unstable, there will inevitably be some graphic glitches, and you shouldn’t expect every OpenGL program to run perfectly. It also has some side effects, notably in terms of making small changes to the way normal windows and menus are displayed. For this reason, we’d advise only enabling the driver if you know that it is going to be useful for some specific program you are using; if you’re not sure whether or not you should be using it, you probably shouldn’t be!

How do I get it?

A full image and a NOOBS installer are available from the Downloads page on this website.

If you are running the current Jessie image, it can be updated to the new version by running

sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install raspi-gpio

To add the experimental GL driver, you will also need to run

sudo apt-get install xcompmgr libgl1-mesa-dri

As ever, your feedback on the new release is very welcome – feel free to comment here or in the forums.

The post Another new Raspbian release appeared first on Raspberry Pi.

Meet BricoGeek: a new Genuino reseller in Spain

via Arduino Blog

bricogeek_blogpost

Some weeks ago we started introducing to the community our list of resellers and the updated page where you can find resellers of Genuino and Arduino products around the world.

We started with Watterott from Germany and now, in the picture below,  you can see Diego and Oscar from BricoGeek  based in Spain and ready to ship  Genuino Uno and Genuino Mega  boards!

Diego-and-OscarBricoGeek01

Let’s get to know them better:

- Tell us a bit more about BricoGeek

We started our company in 2005 and later in 2007 we became one of the first Arduino official distributors for Spain and Portugal. After winning a board in a contest organized by uchobby.com I had so much fun with my new board, I continued to make more projects which I posted in our blog and realised that this little board was really easy to understand and I could make  great things with it. Many of our viewers also enjoyed our projects and started making too. And here we are, 10 years later, sharing projects and growing our community of fellow makers!

- What’s your company’s super power?

We aim to be honest and don’t fool our customers. We try to make BricoGeek a good place to share knowledge and ideas and it seems our customers love that as much as we do.

- What’s your favorite Arduino or Genuino project?

[Oscar] There are so many projects I like and it’s hard to keep track of all of them but I recently discovered a really cool project called “Cubetto” which is a game with a little robot to help kids understand and learn programming. And from the same guys another one called “Toot” also for kids and based on the Montessori learning system. Im working on very similar projects that hopefully I will release them in a few weeks (but shhh it’s a surprise for my daughter! ;D). I really enjoy when I make a project that helps young people learn new technical skills, you will be surprised how smart kids can be when they really enjoy learning.

Contacts

BricoGeek Store Website  – FacebookTwitterYoutube - InstagramGoogle+