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Berlin was a good city to be a geek in last weekend. Alongside the Berlin Maker Faire, there was the 2015 meeting of the Vintage Computing Festival: Berlin (VCFB). Each VCFB has a special theme, and this year it was analogue computers, but there was no lack of old computers large and small, teletext machines, vintage video game consoles, and general nerdy nostalgia.
The first-ever Berlin Maker Faire was last weekend, and Hackaday was there. Berlin’s a city with an incredible creative vibe, so it’s no surprise that there was good stuff on display. What was surprising, though, was how far many of the presenters traveled to be there. I wandered around with a camera and a notebook, and here’s what we saw.
Officially, the latest hardware revision we’ve seen from BeagleBoard is the BeagleBone Black, a small board that’s perfect for when you want to interface hardware to a Linux software environment. This last summer, the BeagleBone Green was introduced, and while it’s a newer hardware release, it’s really just a cost-reduced version of the BB Black. Over the entire BeagleBoard family, it’s time for an upgrade.
It’s been talked about for more than a year now, but the latest and greatest from the BeagleBoard crew is out. It’s called the BeagleBoard X15, and not only is it an extremely powerful Linux board, it also has more ports than you would ever need.
The new BeagleBoard features a dual-core ARM Cortex A15 running at 1.5GHz. There is 2GB of DDR3L RAM on board, and 4GB of EMMC Flash. Outputs include three USB 3.0 hosts, two Gigabit Ethernet controllers, one eSATA connector, LCD output, two PCIe connectors, and an HDMI connector capable of outputting 1920×1080 at 60 FPS. The entire board is open hardware, with documentation for nearly every device on the board available now. The one exception is the PowerVR SGX544 GPU which has a closed driver, but the FSF has proposed a project to create an open driver for this graphics engine so that could change in the future.
The expected price of the BeagleBoard X15 varies from source to source, but all the numbers fall somewhere in the range of $200 to $240 USD, with more recent estimates falling toward the high end. This board is not meant to be a replacement for the much more popular BeagleBone. While the development and relationship between the ~Board and ~Bone are very much related, the BeagleBone has always and will always be a barebone Linux board, albeit with a few interesting features. The BeagleBoard, on the other hand, includes the kitchen sink. While the BeagleBoard X15 hardware is complete, so far there are less than one hundred boards on the planet. These are going directly to the people responsible for making everything work, afterwards orders from Digikey and Mouser will be filled. General availability should be around November, and certainly by Christmas.
While it’s pricier than the BeagleBone, the Raspberry Pi, or dozens of other ARM Linux boards out there, The BeagleBone has a lot of horsepower and plenty of I/Os. It’s an impressive piece of hardware that out-competes just about everything else available. We can’t wait to see it in the wild, but more importantly we can’t wait to see what people can do with it.
Title image credit: Vladimir Pantelic
The philosopher in the street, who has not suffered a course in quantum mechanics, is quite unimpressed by the [Einstein-Podolsky-Rosen] correlations. He can point to many examples of similar correlations in everyday life. The case of Bertlmann’s socks is often cited. Dr. Bertlmann likes to wear two socks of different colours. Which colour he will have on a given foot on a given day is quite unpredictable. But when you see that the first sock is pink you can be already sure that the second sock will not be pink. Observation of the first, and experience with Bertlmann, gives the immediate information about the second. There is no accounting for tastes, but apart from that there is no mystery here. And is this [Einstein-Podolsky-Rosen] business just the same?
John Bell began his now famous paper with the above paragraph. The Bell Inequality started off like so many other great theories in science – as a simple thought experiment. Its conclusions were not so simple, however, and would lead the way to the end of Einstein’s idea of local hidden variables, and along with it his hopes for a deterministic universe. In this article, we’re going to look at the Bell inequality in great detail. Our guide will be a chapter from Jim Baggots’ The Quantum Story, as it has one of the best descriptions of Bell’s theory I’ve ever read.
Continue reading “Bertlmann’s Socks And The Nature Of Reality”
[Philip] got a tattoo of the Hackaday Skull ‘n Wrenches. His job is mostly office work in long sleeves, so everything’s good. The original logo was drawn in Flash by [Phil Torrone] of Adafruit, and reworked into a slightly more modern file format by [Elliot]. Yes, a skull and wrenches is a biker symbol and can be found in the emblem for a few military divisions (mostly for armored support). The Hackaday logo is by far the most cartoonish of all of these Jolly Wrenchers.
Speaking of scrawling the Hackaday logo on stuff, [Rodrick] was bored and needed a distraction last Saturday night.
We’ve seen perpetual motion machines on Kickstarter, and we’ve seen projects that may actually have some basis in reality. We’ve seen 12-year-olds put up a Kickstarter for a new gaming computer, and we’ve seen campaigns to build a bar in some random guy’s basement. There is only one project we haven’t seen on Kickstarter, until now: a campaign to build another crowdfunding platform. It is the Shortening of the Way.
You want a fail? This is a fail. [Chris] is working on a device that combines the familiar Arduino pinout with a CAN transceiver. A good idea, but if you build a PCB, you’re going to need traces. [Chris] sent his files off to our favorite purple board house and got back a sheet of copper laminate with holes in it. A good reminder to check your Gerbers before sending them off.
Live around Denver? There’s a hackerspace in Broomfield, Colorado that’s looking for a new space. They have a Kickstarter for the lease and they’re looking for some people to fill their space.
You kids out there with Pro Tools and Logic don’t know how good you have it. Back in the day, audio was recorded on magnetic tape with exacting mechanical devices called multitrack recorders. [Fran] fished her Otari 8-track recorder out of storage, and it’s a thing of beauty. Also out of storage is a 300 lb+ plate reverb.
[alpha_ninja] proves that Hackaday.io is not just about great projects, but about an awesome community. Over this past week [alpha_ninja] has created The Square Inch Project, which is a grass-roots contest. The contest rules are pretty simple: The project PCB must fit in a 1″ x 1″ square. That’s 2.54 cm for those that don’t use freedom units. Smaller than a square inch is fine. If the project has multiple PCBs like a cordwood module, ALL the PCBs must still fit within the 1″ x 1″ square. Hackaday.io users coming up with cool contest ideas and inviting everyone to take a shot at winning? Awesome!
Of course a contest has to have prizes. [Alpha_ninja] has already lined up $100 in gift certificates to OSHPark. Many thanks to [Laen] and the rest of the OSHPark crew for sponsoring this contest. Hackaday loves the idea so we’re also kicking in eight $50 gift certificates to the Hackaday store, as well as four more $25 gift certificates to OSHPark.
Though the contest has been up for less than a week, the square inch project already has some great entries.
[Drix] has entered Twiz, a 9 degree of freedom Inertial Measurement Unit (IMU) with Bluetooth Low Energy (BLE) connectivity. Twiz senses its environment with a MPU9150 IMU chip. A nRF51822 provides the Bluetooth connection and ARM Cortex-M0 processor. Put all this together, and you’ve got a great way to determine where an object is in space. [Drix] has used Twiz to control everything from holographic projectors to room lights. Contests aren’t new to [Drix], he’s already entered Twiz in the 2015 Hackaday Prize.
[WeisTekEng] has entered Micro DIY Lipo retro NumiTron clock. [WeisTekEng] loves the classic IV-9 Russian numitron tubes. His plan here is to build a numitron clock driven by an ATmega328 microcontroller. The timebase for this clock is also a classic — The Dallas Semiconductor (now Maxim) DS1307 I2C real-time clock chip. Everything is going to run on a single LiPo cell. Fitting within the project constraints, the board will be only 1″ square. This is [WeisTekEng’s] first big project on Hackaday.io, so we’re happy to see him join the community. He’s also just getting started, so the PCB’s only exist in the virtual word of his EDA software for now. We’re looking forward to reading the numitron clock!
[Al1] has entered tiny7, a 7 segment display which is compatible with Atmel ISP headers. Ever notice those 6 pin headers on the Arduino? That’s the ISP connector, used to program the ATmega328 micro. In many designs these valuable IO pins spend most of their time unused. [Al1] decided to give them a purpose – displaying data! He’s connected a 75HC595 shift register to the SPI pins of the ISP header. Data clocked into the ‘595 is displayed on a 7 segment display. [Al1] designed the boards with castellated connections on the sides. Some careful soldering allows the boards to be daisy chained. Several 7 segment displays to be driven from a single ISP header.
[Radomir Dopieralski] is using The Square Inch Project as a learning platform as well. He’s entering Nyan Board, a tiny PCB shaped like everyone’s favorite rainbow pooping cat. [Radomir] is using nyan board to learn how to work with ATtiny microcontrollers. Due to memory constraints, these little controllers can be a bit harder to program than their bigger brothers. [Radomir’s] early goals for Nyan are humble ones – he will be happy to have the cat’s eyes flash while it plays the Nyan Cat tune. Once that task is complete, the RAM and Flash of the ATtiny microcontroller will be his only constraints.
The contest deadline isn’t until November 28, 2015, so there is still plenty of time to enter. If you want to see more of the entrants, check out The Square Inch Project page, or the entrant list. Want to know more? Ask a question on the project page, or drop [Alpha_Ninja] a message!
That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!
Welcome to part three of “Interrupts: The Good, the Bad, and the Ugly”. We’ve already professed our love for interrupts, showing how they are useful for solving multiple common microcontroller tasks with aplomb. That was surely Good. And then we dipped into some of the scheduling and priority problems that can crop up, especially if your interrupt service routines (ISRs) run for too long, or do more than they should. That was Bad, but we can combat those problems by writing lightweight ISRs.
This installment, for better or worse, uncovers our least favorite side effect of running interrupts on a small microcontroller, and that is that your assumptions about what your code is doing can be wrong, and sometimes with disastrous consequences. It’s gonna get Ugly
TL;DR: Once you’ve started changing variables from inside interrupts, you can no longer count on their values staying constant — you never know when the interrupt is going to strike! Murphy’s law says that it will hit at the worst times. The solution is to temporarily turn off interrupts for critical blocks of code, so that your own ISRs can’t pull the rug out from under your feet. (Sounds easy, but read on!)
Continue reading “Embed With Elliot: Interrupts, The Ugly”
